196 Memoir Sears Foundation for Marine Research 



mesopterygium much smaller, with few radials; meso- and metapterygia separated by a 

 foramen, or not ; vertebral calcifications widely variable in type j heart valves In 2 or 3 rows. 

 Development oviparous so far as known. 



The family includes numerous species of small sharks In tropical and temperate lati- 

 tudes, from both shoal water and deep. Although it embraces two of the most common 

 and best known of the European sharks," the centers of abundance for both genera and 

 species are the western Pacific, Australasian region and Indian Ocean to South Africa. It is 

 represented in the western North Atlantic by only a few little known deep water species. 



Genera. Opinions have differed widely as to the number of genera deserving recog- 

 nition In this family. At the one extreme Carman' recognizes eleven, a list to which no 

 less than seven more genera or subgenera have subsequently been added by Fowler* and 

 Whitley." At the other extreme Barnard" unites In a single genus the ten South African 

 representatives of the family, which would fall in some seven different genera under the 

 contrasting scheme. An intermediate view Is taken by Norman, who suggests the recogni- 

 tion of "some four natural groups as genera."^ 



Generic characters In so uniform a family must be based on definitely alternative 

 and easily discernible characters to be of any value to working Ichthyologists. For Instance, 

 one group of some nine recognizable species is set apart from all other members of the 

 family by the fact that the denticles along the dorsal margin of the anterior part of the 

 caudal are not only enlarged but modified In shape and directed laterally so as to form 

 a definite crest, which is outlined below by a narrow band of naked skin.' The mem- 

 bers of this group fall into two categories: one with the posterior margin of the nos- 

 tril widely expanded, the snout short and thick and the body cavity longer; the other 

 with the posterior margin of the nostril expanded little, if at all, the snout long and 

 thin and the body cavity shorter. These characters seem sufficiently alternative for the 

 retention of the genus Parmaturus Carman, 1906, for the first group, as distinct from 

 Galeus Rafinesque, 18 10, for the second. But Whitley's segregation of some members 

 of the latter into a separate subgenus {Figaro) because of the presence of a crest on both 

 lower and upper sides of the caudal peduncle seems to us an unnecessarily minute sub- 

 division. Among the other Scyllorhinidae Pentanchus profundicolus Smith and Radcliffe, 

 1912,° and another unnamed species^" are set apart from the rest and from all other galeoid 

 sharks by the fact that they have only one dorsal fin." Among the species that remain after 

 subtraction of the foregoing, the first dorsal of one, Catulus cephalus Cllbert, 1 891, orlgl- 



2. Scyliorhinus caniculus Linnaeus and S. stellaris Linnaeus, the so-called Spotted Dogfishes. 



3. Mem. Harv. Mus. comp. ZooL, jd, 1913 : 68 [Catulidae]. 



4. Proc. Acad. nat. Sci. Philad., Ss, 1934: 233- 5- Aust. Zool., 9, 1939: 227- 



6. Ann. S. Afr. Mus., 27 (i), 1925; 39. 7. Nature, Lend., /.;«, 1941 : 7- 



8. These fish are commonly called File Tails in California. 



9. The type specimen, now in the U.S. National Museum, shows no sign of mutilation. It is further interesting for the 

 fact that its gill openings are of the character pictured in Fig. 38, 39 for Afristurus frofundorum and A. riveri. 



10. A Japanese scyliorhinid with only one dorsal fin is briefly described, but without specific name, by Jordan and 

 Hubbs (Mem. Carneg. Mus., 10, 1925: 100). 



11. Jordan and Hubbs (Mem. Carneg. Mus., /o, 1925: 100) also suggest that the doubtful genus Caninoa of 



