ORDER HEMIBRANCHII

FAMILY Gasterosteidæ (The Sticklebacks)

The Brook Stickleback, Eucalia inconstans (Kirtland), is reported by Henshall from Poplar R., Montana. It has 4 or 5 dorsal spines.

ORDER ACANTHOPTERI (The Spiny-Rayed Fishes)

FAMILY Aphredoderidæ (The Pirate Perches)

Dorsal fin single, with few small spines. Vent anterior, its position varying with age, from just behind the ventral fins in the young, to below the preopercle in the adult. One genus and species among living fishes, confined to the eastern United States. The group is so distinct that Jordan and Evermann place it in a distinct suborder, Xenarchi.

No less than four genera of these fishes have been described by Cope from the Rocky Mountain Tertiaries. Jordan and Evermann remark that these fossil genera "seem to stand between Aphredoderus and Elassoma, which seem to be near relatives on the one hand, as Percopsis is on the other."

The fossils are:

Trichophanes foliarum Cope, and T. copei, Osborn, Scott and Speir, Miocene shales of Florissant, Colorado.

Amphiplaga brachyptera Cope, Asineops pauciradiatus Cope, A. squamifrons Cope, Erismatopterus endlichii Cope, E. levatus Cope, and E. rickseckeri Cope, all from the Green River beds of Wyoming.

FAMILY Mugilidæ (The Mullets)

Two short dorsal fins, well separated, the anterior with four stiff spines, of which the last is much the shortest.

Pelecorapis berycinus Cope, is from the Pierre Cretaceous of Montana.

Syllamus latifrons Cope, is from the Benton Cretaceous, doubtfully of New Mexico. FAMILY Centrarchida (The Sunfishes)

Body more or less shortened and compressed. Dorsal fins confluent.

Jordan and Evermann say: "fresh-water fishes of North America; genera 12; species about 30, forming one of the most characteristic features of our fish fauna." They appear to be very few in the vicinity of the Rocky Mountains, however.

Dorsal fin scarcely longer than anal; silvery olive, mottled with clear olive green (Boulder
County, introduced: Juday).
Pomoxis sparoides (Lacép.)
(Calico Bass).

Dorsal fin much larger than the anal

I.

1. Body comparatively elongate, the depth of adult about one-third the length; dorsal fin low, deeply emarginate, with 10 spines.

Body comparatively short and deep; dorsal fin not deeply emarginate

2.

3.

2. Mouth moderate; young more or less barred or spotted, never with a black lateral band (introduced in Montana)

Micropterus dolomieu Lacép. (Small-mouthed Black Bass).

Mouth large; young with a blackish lateral band (introduced in Boulder Co., Colo., and Montana) .

Micropterus salmoides Lacép. (Large-mouthed Black Bass).

3. Dorsal spines strong and high, the longest usually longer than snout and eye; olive green, adults dark; sides with undulating greenish bars, becoming obsolete in adult (Rio Grande). Lepomis pallidus (Mitchill) (Blue-gill). Dorsal spines low, the longest little longer than snout 4. Brilliant blue and orange, the back chiefly blue, the belly entirely orange; cheeks orange with bright blue stripes; length 8 inches. (Rio Grande) Lepomis megalotis (Raf.) (Long-eared Sunfish).

4.

The prevailing shade green, with a strong brassy luster on sides, which becomes nearly yellow below; each scale usually with a blue spot. (Boulder County, Juday; Rio Grande) A pomotis cyanellus (Raf.) (Blue-spotted sunfish). Spirit specimens of A pomotis cyanellus are a sort of bluish-gray or pale plumbeous, with a faint lattice-marking, and scattered small dark spots. The fish is quite unlike any other native in Boulder County.

Mioplosus Cope, is a genus of the Green River Shales of Wyoming, with the following species: M. abbreviatus Cope, M. beani Cope, M. labracoides Cope, M. longus Cope, M. sauvageanus Cope.

The living forms are as follows:

Large fishes, with preopercle serrate; mouth large, terminal

Small fishes, preopercle entire or nearly so

I.

2.

1. Canine teeth none; body oblong; ventral fins near together; back dark olivaceous, sides golden yellow, with 6 or 8 dark bars (Montana, introduced)

Perca flavescens Mitchill (Yellow Perch).

Canine teeth on jaws and palatines; body elongate, head with a snakelike aspect (Upper Missouri R.) Stizostedion canadense boreum Girard. (Northern Pike-Perch).

2. Only one anal spine (A I, 7 to 9); length of fish about or nearly 70 mm.; scales larger than in E. iowa, about 1 mm. across; eye about 13 mm. from mouth; dorsal fins touching, or slightly separated; parietal region of head concave. (Boulder Co., Juday) Boleosoma nigrum Raf.

Two anal spines; anal rays 6 to 8

3.

3. Humeral region with a distinct black process or scale; scales 46 to 55 in lateral line; snout much shorter than eye (Cañon City, Colo.) Etheostoma cragini Gilbert. Humeral region with at most a faint dark spot

4.

4. Head entirely scaleless; scales 6-48 to 54-8; olivaceous, with dark blue bars. (Dimmit Lake, near Roswell, N. M., Cockerell). Etheostoma lepidum Baird and Girard. Head partially scaly; scales 5-55 to 63-11; length about 55 mm.; scales a little over I mm. across; eye about mm. from mouth; dorsal fins distinctly separated. (Boulder Creek, Boulder, Nov. 1907.) . . Etheostoma iowa Jordan and Meek.1 FAMILY Pomacentrida (The Demoiselles)

Fishes of tropical seas. Nostril single on each side, nearly round, a character "shared with the Cichlida only, from ancestors of which group the Pomacentrida are probably descended."

Priscacara Cope is a genus of the Green River shales in Wyoming, with these species: P. clivosa Cope, P. cypha Cope, P. hypsacantha Cope, P. liops Cope, P. oxyprion Cope, P. pealei Cope, P. serrata Cope. A good example of P. liops (with, however, 14 caudal vertebræ instead of 13) is in the Museum of the University of Colorado (Maxwell collection).

Caudal peduncle very slender, its least depth not much greater than diameter of eye;

body and head profusely speckled (Green River, Wyoming). Cottus punctulatus Gill. Caudal peduncle deep, its least depth equal to length of snout; back and sides less distinctly speckled

.

I.

1. Head blunt, low, rounded anteriorly; body with vague dark clouds and specks. (Colorado, New Mexico, Wyo., Mont.)

Cottus semiscaber Cope (Rocky Mountain Bullhead). Head less rounded, with a median depression; body usually with broad, oblique, dark bars; small and slender; the spinous dorsal very low. (Swan R., Montana, Linton, possibly in error for semiscaber) Cottus ictalops bairdii Girard.

Scales small, cycloid; mouth large; chin with a barbel. Marine, except Lota. Anal fin not notched; length of fish 2 feet; barbel longer than eye (Montana).

Lota maculosa Le Sueur (Burbot or Ling).

E. iowa seemed far out of range, but I sent a speciman to Dr. Evermann, and he reports that it agrees well with typical specimens from Iowa and Nebraska.

THE SANDSTONE OF FOSSIL RIDGE IN NORTHERN COLORADO AND ITS FAUNA

BY JUNIUS HENDERSON

Fossil Ridge is a low ridge of sandstone extending in an approximate north-south direction for several miles, lying between the Colorado and Southern Railway track and the Ft. Collins-Loveland wagon road, south of Ft. Collins. Fossil Creek cuts through the ridge about five miles south of Ft. Collins, near where the ridge in its northward extension passes into the general level of the divide and thus disappears. Weathered out on the surface of this sandstone are innumerable hard, sandy concretions, from a few inches to four feet in diameter, containing large numbers of fossils, which have given to the ridge and creek the names they bear. The large size and abundance of some of the species attract the attention of even the most unobserving traveller who passes over the ridge. In the early reports the locality was variously called Fossil Ridge and Fossil Creek. As the ridge follows a definite stratigraphic horizon, while the creek cuts across strata several thousand feet in thickness, the former name seems preferable in a geological sense.

This vicinity is of peculiar interest to the paleontologist as the type locality of some interesting forms, as well as because of the pronounced intermingling of Pierre and Fox Hills species. A correct understanding of this and related sandstones may also have a very practical value in the exploration for oil.

These beds seem to occupy a position about one-third of the way up from the bottom of the Ft. Pierre Cretaceous. As the Pierre in this region is from 5,000 to 7,000 feet in thickness, the importance of finding narrow, persistent, identifiable horizons, either lithological or paleontological, within the formation, is at once apparent. Oil of excellent quality and in paying quantities is found in the Pierre at several places in Colorado, as at Boulder and Florence. There is every reason to believe that the production of petroleum may be greatly increased by

intelligent prospecting along the plains bordering the foothills of eastern Colorado, but the prospecting thus far has resulted in a vast amount of dead work upon which the comparatively few producing wells must pay interest in order to make the industry on the whole a profitable one. The accumulation of oil in the rocks is known to be controlled largely by folds. The great thickness of this formation, its homogeneity and the lack of closely connected outcrops over large areas render the accurate determination of such structural features very difficult. For this and other reasons the prospecting has thus far been carried on chiefly by haphazard boring, the location of many borings having been based upon the use of the "bobber," the finding of horseshoes and rabbit tracks and other

superstitious methods. In consequence many holes have been put down where more thorough and systematic prospecting would have shown their probable folly and more likely ground has been wholly overlooked. Where the oil is reached at a depth of hundreds of feet, as here, the expense of dry holes is an item to be seriously considered. Hence the growing demand for a better understanding of the Pierre formation.

FIG. 1.-Map showing relation of Hygiene sandstone to older formations of foothills, prepared by Mr. H. F. Watts from the writer's data.