372 U. 8. p. H. R. EXP. AND SURVEYS — ZOOLOGY — GENERAL KEPOET. 



is immovable; the eyes and the spiracles separated by a small bridge; the spiracles exhibiting 

 a smooth border. The nasal flaps coalesce into a quadrangular lip, which is united to the edge 

 of the anterior jaw, a small portion alone remaining free on either side, under the shape of a 

 rounded angle more or less fringed. At the outer edge of the nasal apertures may be observed 

 a small membranous border. The mouth is bent forwards, without cartilaginous iips. The 

 teeth are acute or pavement-like, depressed, although pointed or acute in the male sex during 

 the breeding season. A maxillar membrane at the upper (anterior) jaw only, emarginated in 

 the middle, and fringed upon its edge. The skin is either smooth or covered with small, 

 curved spines directed backwards, more or less crowded according to the species. Larger 

 spines are also occasionally intermixed along the dorsal line and tail, on the sides of the tail, 

 the eyelid, or around the orbit, on the rostral ridge, and at the anterior edge of the pectoral 

 fins. In the male sex, during the breeding season, are developed two sharp spines at the 

 anterior margin of the pectoral fins. The female sex lays eggs. 



Sr.s'.— iiojini, Bokap. Syst. Vert. 1837, 44 ; &, Selacli. Tabul. analyt. 1838, 4.— Bd. Iconogr. Eneycl. II, 1850, 243. 



liajnc, Mull. &. Henle, Syst. Besclir. PJagiost. 1841, 132.— Mdll. in Wiegm. Arcliiv fiir Naturg. 1845, I, 137. 

 Raiidae, Owen, Leet. Coinp. Aiiat. Vortcbr. Anitn. 1846, 51. 



The rays properly so called, and which constitute the present family, are the only ones in 

 the sub-order to which they belong that lay their eggs ; the latter being, in the other families, 

 retained in the abdominal cavity till after hatching. 



KAJA, A r t e d i . 



Gen Char. — The snoot is prodnccd into a keel, to which the inner margin of the pectorals is parallel. Ttic intervening 

 space between the rostral keel and the inner margin of the pectorals is skinned. The ventral fins subdivide into an inner and 

 an outer lobe, resulting from a deep emargination of their posterior margin ; the outer lobe being thicker but smaller than the 

 inner. The tail is provided wifh a low terminal fin, more conspicuous at the upper than at the lower aspect, and generally 

 nterr upted towards the apex. 



Syn.— iJrtjfi, AnTCDi,'Gcn. Pise. ed. TValbaumi, 1792, 523.— Likv. Syrt. Nat. ed. Xlla I, 1766, 390.— Gmel. Linn, Syst. 

 Nat. XIII" 1, III, 1788, 1504.- Cuv. Rt-gn. Anim. II, 1817, 134 ; 2d ed. II, 1829 ; & ed. ill. Poiss. 373.— Mdll. 

 6i Hekle, Syst. Besclir. Piagiost. 1841, 1.32.— De Kat, N. Y. Faun. IV, 1842, 366.— Storer, Rep. Fish. 

 Mass. 1839, 191 ; &, Synops. 1846, 258.— Dum. Iclithyol. analyt. 1856, 137 & 142. 



The species of the genus Baja, even as restricted by modern writers, are still very numerous, 

 distributed nearly all over the globe. Miiller and Henle have made two divisions of them. 

 1. Those in which the snout is rather blunt and the rostral keel not extending to the edge of 

 the disc ; and 2. Those in which the snout is more pointed or acute and more or less elon"-ated : 

 the latter division including more species than the former. The species hereon alluded to, would 

 belong to the second division, and should future observations restore the genus Laeviraja, it is 

 to that genus that it will revert. 



KAJA COOPERI, G r d . 



This species came to our knowledge through a sketch made by Dr. James G. Cooper, 

 accompanied by the following remarks : 



"In June and July, 1854, several large skates were washed ashore on the sand flats near 

 the entrance of Shoalwater bay, and which I had no means of preserving. I took a sketch 

 oFone of the largest, of which ihe inclo.sed is a copy. 



" Though I did not see any of them alive, I think they had entered the bay and were left by 

 the ebb-tide on some of the extensive sand bars, where they had died. I have never heard of 



