On new Genera and Species of Californian Fishes—No. II.

BY J. G. COOPER, M. D.

Exocœtus, Artedi.

E. Californicus, Cooper, Californian Flying-Fish, State collection, species 1012. [[Fig. 20.]]

Fig. 20.

Specific characters.—Height of body one eighth of its length from tip of nose to fork of tail, length of head almost one fifth of the same (0·19). Width of forehead in front of eyes more than five eighths the length of head (0·69); diameter of eye less than one third of same length (0·30). Scale between eyes equilateral, and a little less than half of the width of head. No granulated area in front of orbit, and but a very narrow one behind it. Preoperculum rounded rectangular. Pectoral fin extending to halfway between end of dorsal and base of caudal, 0·60 of total length. Ventrals inserted nearer operculum than base of caudal, and extending to middle of anal. Dorsal commencing over 36th scale and extending to 48th.

D. 12, P. 14, V. 6, A. 10, C. 3-1-4-5-1-6. Scales 58-7/1.

Colors.—Steel-blue, fins smoky, below silvery, iris gilt.

General form much elongated, subcylindrical. Top of head perfectly flat, its width equal to its depth. Anterior half of body nearly as broad as high, compressed above. Posterior half compressed laterally, tapering to tail, the caudal peduncle three times as high as it is broad. A slight ridge along insertion of dorsal. Lateral line prominent, running close to insertion of ventrals. Proportions of fins to total length, as follows:

Length of dorsal0·11
Height of ventrals0·23
Length of anal0·07
Length of caudal, upper lobe0·15
Length of caudal, lower lobe0·22
Height of pectoral0·60

Length of specimen fifteen inches, the figure representing it half the natural size. One specimen obtained at Catalina Island.

Remarks.—In the preceding diagnosis I have followed the arrangement of specific characters adopted by Gill in his description of two new species of Exocœtus from the Pacific Coast of Central America. (Proc. Acad. Phil., June, 1863, p. 167.) By comparison it will be seen that our species is very distinct.

This large species of Flying-Fish is found in great numbers during the summer south of Point Conception, and some wander as far north as Santa Cruz at least. They can only be taken when they happen to alight on board of a vessel or in gill-nets, which I was not provided with during my late voyage among the islands. Their flight is rarely higher than ten feet above the water, but sometimes extends nearly a quarter of a mile.

Urolophus, Müller and Henle.

Urolophus Halleri, Cooper, State collection, species 522. [[Fig. 21.]]

Fig. 21.

Specific characters.—Disk suborbicular, obtusely pointed in front, and with the pectoral fins rounded behind. Length anterior to anus a little greater than that of the tail behind it. Posterior outline of ventral fins projecting a little behind that of disk. Claspers as long as ventrals and projecting entirely behind them. Tail 0·47 of total length, gradually tapering from a cylindrical base to the spine, thence becoming flattened laterally expanding into a fin, which commences opposite the base of spine below, and ends opposite to its end above, broadest near its end, where its width is 0·10 the length of tail. Spiracles a little larger than orbits and farther apart, the distance between them equal to that from snout to orbits. Ventrals forming nearly equilateral triangles, their basal length one fifth that of head and body. Caudal spine arising at 0·48 of the length of tail, and not quite one third as long. Female more elongated than male but tail and spine shorter; the ventrals a fourth longer and more acute.

Colors.—Reddish speckled with yellow, below white. In some specimens the dark and light colors above are about equally distributed, the spots having a somewhat marbled arrangement. In others the light spots are very few and widely separated. Popular name “Round Stingray.” The figure is half the natural size. The dots show the principal outlines of the cartilaginous skeleton.

Remarks.—While this fish has the nearly orbicular outline of Urotrygon (mundus), Gill, from Panama (Proc. Phil. Acad., June, 1863, p. 173), it differs generically in having obtusely triangular teeth (equilateral), tail shorter than body, spine nearest to its base, smooth skin, etc.

It differs from Urolophus, as described by Richardson, in the upper velum of mouth being entire, and in having about twenty small tubercles on the surface of lower velum. These however can scarcely be considered generic differences.

Found abundantly in muddy creeks at San Pedro and San Diego, those from the former place being more uniform in color.

While I was at San Diego the little son of Major G. O. Haller, U. S. A. was wounded in the foot, probably by one of these fish, while wading along a muddy shore of the bay. The wound was very painful for some hours, though small. Another large rhomboidal species also abundant there but apparently still undescribed, inflicts very severe and dangerous wounds, of which I may have more to say hereafter.

This fish has great muscular power and can dart very rapidly through the water by lateral vibrations of its tail, at the same time quickly flapping the edge of its disk, to keep its level in the water and to regulate its direction.

It frequently buries itself slightly under the mud, and if disturbed obscures the water by stirring the mud, vanishing in the cloud thus raised to hide itself again. It will allow a boat to pass over its place of concealment, and may, if detected, be easily killed by a blow with the end of an oar. Many are also caught in the seines of the fishermen.

Their food consists of small mollusca, crustacea and such other animals, alive or dead, as they can obtain.