16 DKEP-SEA FISIIKS OF TIIK ATLANTIC BASIN. 



Tho family, as thus defined, embraces i<!r!/llii(>ii, rristiiiru.s, Stcf/osloma. PKnisri/lUiim, 

 Chiloxcyllium, and related {genera. They are inhabitants entirely otthe seas of the Old 

 World and Australia, none beiiiR found iu Amerieau waters. They are amonj;- tlie tew 

 sharks whieli lay ejigs invested in paiehment-like eases, like those of the rays. 



KEY TO THE ATLANTIC GENERA OF SCYLLIOKHlNIDyE. 



(Ailaptril from Giiutber. ) 

 [. Nasal and tiiiccal ra\iti(^s separate. 



A. Caudal tin witli uppor odjrcs entire. 



1. First dorsal short, elevated; anal origin in advance ofseeond dorsal Scylliorihnts 



2. First dorsal long, very low; anal origin behind tlmt of socond dorsal Pskidotuiacis 



15. Caudal tin with uppor edges serrated PiasTiriU's 



n. Nasal and Imccal eavities confluent. 



C. Second dorsal iiu nearly opposite anal (iixiiLVMusTii.MA 



Other genera, Stegostoina, rarasvyllinm, ChiloscyUium, and VroKnorhiiiKs are peenliar to 

 oriental faunas. Ginghjmostoma is a shallow-water form, inhabiting warm waters. Few 

 si)ecies of Sci/lliiim have been found at considerable depths. 



This family is nearly cosmoi)olitan, but has no representatives in either the western 

 Atlantic or in the eastern Pacific, except a single Scyllium on the coast of Chile. 



SCYLLIORHINUS, BlainviUe. 



Seyllhrhinu^, lii..\iNvn,i,i.: (.Ionian and Gilbert, Bull, xvi, U. S. Nat. Mus., 1883, 869). 



ScyUium, Crvn-,i!, Kigue Animal, 1829, n, 386.— Millkk and Hkni.k, S. B. Plag., 3.— GCntheh, Cat. Fish. 

 Brit. Mus., VIII, 400.— Day, Fish. Gt. Britain and Ireland, ii, 309.— Gill, Ann. Lye. Nat. Hist., in, 407. 



Spiracles behind the eyes. Nasal cavities distinct from that of the mouth. Teeth 

 small, iu many rows, usually with a central and one or two lateral cusi)s. Origin of anal 

 fin in advance of that of the second dorsal; upper edge of caudal not serrated. [Day.) 



SCYLLIORHINUSRETIFEIt, ((i.vuMAN). (Figures 14, 1.5.) 



»Sc//??iK»i >T/i/«-Hm, Garman, Bull. Mus. Comp. Zoiil., 1881, viii, No. 11,233. — Goodk and Bkan, Hull. Mus. 



Coinp. /oiil., vol. X, No. 5, 226. 

 Scylliorhiniis retifer, Jordan, Cat. Fish. N. A., 1885, 5. 



r.ody moderate, portion behind the vent longer; head d«>pressed, width nearly ecjual to 

 its length in front of the spiracles. J >istance across the head at anterior angles of eyes, from 

 angle of eye to end of snout, between angles of mouth, between outer angles of nostrils, or 

 between angle of nostril and that of mouth, about e(iual. Shape of body similar to that of 

 8. caniculd. Snout moderate, length from mouth less than the distance between the outer 

 margins of the nostrils. Nasal valves separated by an interspace of less than their width, 

 not reaching the month, somewhat fi)lded, without a fri'e cirrus. Mouth medium ; the height 

 of the iriegular arch formed by its outline is little more than half its width. Labial fold 

 on lower jaw extending nearly one-fourth of the distance to the symphysis; fold on upper 

 jaw rudimentary. Teeth small, alike on u])i)er and lower .jaws, bearing a sharp central 

 cus]), on eacli side of which are two smaller ones, several series iu function at the same 

 time. No nictitating membrane. Spiiai;les small. (Jill openings small, fourth and filth 

 over the base of the xieetoral. Pectorals moderate, broad, short, anterior margins curved, 

 extremities rounded. Ventrals rather small, united fi)r a short distance behind the tilaspers, 

 outer extremity broadly rounded, posterior an.gle acute. First dor.sal much larger than the 

 second, about twice the length of its base in advance of the latter, extending fi)rward above 

 the free portions of the ventrals, insertion very near the middle of the total length. Second 

 dorsal smaller than tlu^ anal, which extends below the anterior half of its entir(> length, not 

 reaching the caudal. (Jaudal not large, a shallow notch between its upper and lower 

 lobes, upper slightly indented on its hinder margin. Scales of shagreen small, unequal; on 

 those of the back there are three or five carina', the median of which is prolonged into an 

 acute i)oint. 



