fins and on both the upper and lower lobes of the 

 caudal fin. 



Species described as Catulus haeckelii Miranda- 

 Riheiro, 1907, and as Scyliorhinus fernandezi 

 Weibezahn, 1953, are regarded here as being syn- 

 onymous with S. boa. The geographical range of 

 S. boa extends at least from the continental slope 

 of central Venezuela eastward and southward to 

 Rio de Janeiro where it was taken by Miranda- 

 Ribeiro (1907). Dr. Elvira M. Siccardi has told 

 me (personal communication) of the presence of 

 S. boa or a closely allied population off the north- 

 erly coast of Argentina. A photograph of one 

 specimen shows somewhat longer and larger black 

 spots than characterize the specimens seen from 

 Venezuela and the Guianas. Whether the juvenile 

 specimen reported by Bigelow and Schroeder 

 (1948) from the north coast of Cuba is correctly 

 identified as S. boa now appears questionable. 

 Material examined in this study in addition to 

 the type is from 10 stations of the M/V Oregon 

 off the coasts of Venezuela, the Guianas, and 

 Brazil, from lat, 11°34' N., long. 62°52' W., to hit. 

 01°52' N., long. 46°54' W., in 293 to 402 m. 



The teeth in S. boa in specimens examined were 

 from 24 + 24/21 + 1 + 21 to 25 + 25/23 + 1+23. The 

 teeth were somewhat smaller than the teeth of other 

 western Atlantic Scyliorhinus of similar size. 

 Also the central cusps are comparatively shorter, 

 and nearly all teeth have five cusps, with only teeth 

 of the central part of the upper jaw having the 

 middle cusp of each tooth twice as long as the cusps 

 next to it. 



The dermal denticles of the dorsolateral sur- 

 faces differ from the denticles of S. meadi in being 

 smaller, wider (some of them nearly as wide as 

 long), set. closer together, and less erect. The 

 denticles of 8. boa differ very little from denticles 

 of other Atlantic American members of the genus. 

 Denticle differences due to age and perhaps also to 

 intraspecific variation are so great, however, that 

 these are probably not ordinarily useful in identi- 

 fying material. 



S. boil seems to he a smaller species than S. 

 retifer or S. hesperius, since a 346 nun. male is 

 sexually mature. The claspers of I his male reach 

 4 mm. past the tips of the pelvics which are united 

 to one another along their inner margins to within 

 6 mm. of their tips. The claspers are not provided 

 with hooks hut have a few slightly enlarged den- 



ticles which have points directed anteriorly (to- 

 ward the base of the claspers) as in the denticle 

 arrangement on claspers of all galeoid sharks. 



Scyliorhinus retifer (Garman), 1881 

 Figures 2, 5, 6, 7. 8, and 27 ; tables 1. 3, and 4 



Soyllium retiferum Garman, Bull. Mus. Comp. Zool. 

 8:233, 1881 (type locality, lat. 38°23' N., long 73°34' 

 W.). 



This species is easily recognized by its unique 

 pattern of reticulating lines sometimes reduced to 

 black edging lines along margins of saddles and 

 blotches. It is the only Atlantic American cat- 

 shark known well enough to have acquired an 

 English common name, the chain dogfish. It is 

 frequently taken by trawlers operating off the 

 Virginia Capes. 



The known range of the species extends from the 

 offing of southern New England and the south- 

 western edge of Georges Bank to Nicaragua. 

 Bigelow, Schroeder, and Springer (1953) note 

 that it has been taken at depths of 73 to 229 m. 

 in the northern part of its range. Specimens of 

 S. retifer have been seen from more than 100 sta- 

 tions of Bureau of Commercial Fisheries Explora- 

 tory Fishing vessels between the Virginia Capes, 

 the lower Gulf of Campeche, and off central Nica- 

 ragua (lat. 13°30' N., long. 82°00' W.), along the 

 continental slope. The station with the least depth 

 was at 165 m. off Cape Henry, Va., where over 

 500 juveniles about 160 to 200 mm. long were taken 

 in early May, 1961. Southward the collections 

 were at greater depths, for the most part from 330 

 to 450 m. off Florida and in the Gulf of Mexico, 

 but 500 to 550 m. off Nicaragua. One specimen 

 of S. retifer was taken from M/V Oregon station 

 1883 on the continental slope off Honduras at 365 

 m. where a specimen of S. hexperius was also taken. 

 Southward from this station along the continental 

 slope for a distance of about 200 miles, where the 

 two forms occupy adjacent or nearly overlapping 

 ranges, *S'. retifer was taken in an average depth 

 of 525 m. (460 to 550 m.) at 16 stations, while .V. 

 hesperius was taken at an average depth of 400 

 m. (274 to 530 m.) at 7 stations. 



A peculiarity of the distribution of S. retifer 

 is that records of it occurrence on the Antilles!) 

 side of the Straits of Florida (off Cuba and the 

 Bahama Banks) are absent. X. torrei records are 

 chiefly from this area, and one of the three sta- 



6(12 



U.S. FISH AND WILDLIFE SERVICE 



