ACADEMY OF NATURAL SCIENCES. 95 



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 sum- 

 mer 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 some- 

 times extends nearly a quarter of a mile. 



Urolophus, Midler and Henle. 



Urolophus Halleri, Cooper, State collection, species 522. [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 47 of total length, gradually tapering from a cylindrical base to 

 the spine, thence becoming flattened laterally expanding into a fin, which com- 

 mences 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. Yentrals 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. Iu some specimens the 

 dark and light colors above are about equally distributed, the spots having a 

 somewhat marbled arrangement. Iu 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. 0. Haller, IT. 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. 



