870 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY IV. 



torals short and broad. First dorsal inserted near middle of length of 

 bodyj caudal not large. (Odrman.) Deep water, off the coast of Vir- 

 ginia; one specimen known. 



(Sryllium retifcrttm Gannan, Bull. Mus. Comp. Zool. xi, 233, 1881.) 



Page 18. Instead of GaleorhinidcBj read: 



FAMILY VII. CARCHARIIDJS. 



On page 19, instead of Mustelus hiunulus, read: 

 19. II. ranis (Mitch.) Dek. 



Add to the synonymy: 



("Squaltts cam's Mitch. Trans. Lit. & Phil. Soc. N. Y. i, 486, 1815: Nustelits asterias 

 Cloquet, Diet. Sci. Nat. xiv, 407, 1820: Muslelua plebejas Bouap. Faima Italica, 1838, 

 49.") 



Page 20, species 20 : 



The Jlustclus canis of our Atlantic coast seems to ns to be perfectly 

 identical with the European species, the American name having prior- 

 ity of date. Mustelus cnJifornicua Gill, is however a different species. 

 I r may be thus compared with M. canis, the differential characters of the 

 latter species being interposed in parenthesis: In Ko. 20, M. i-uHforni- 

 CHH Gill, the dorsal fin is comparatively small (large), its anterior lobe 

 obtuse, and when depressed not reaching so Car as (reaching well be- 

 yond) the posterior lobe; height of anterior lobe less (more) than the 

 base of the fin, which is little (considerably) longer than snout and less 

 (more) than one-third the interspace between dorsals; the pectoral is 

 comparatively short, not reaching to anterior third (reaching nearly to 

 middle) of dorsal, or about half way to the beginning of the slit be- 

 tween vent nils (half way to the base of the claspers). The snout in 

 I/. i-<ii;/<-ni<-nK is more pointed, the mouth narrower, its anterior angle 

 more acute (obtuse); breadth between angles of mouth rj (;|) snout. 

 lifon/ii'i/s reaches a larger si/.e than M. run!*. In Musti-liix 

 the embryo is attached to the placenta-. It therefore be- 

 longs to the subgeims " Pleuracromylon" Gill. 



1'aue LMI. The genus '/,'// i tint rindx." introduced on page .">!)., may be 

 .suppressed, k '7i'. lunl, i'" brin.u a s[)ecies of Trim-i*. as gi\cn on page 20. 



Page L'O ((>(>). LM) (/>), L'hi imtriacis Iccvia" (or, better, Miixtetus Iccvis 

 Uisso) should probably be suppressed, as tin- evidence of its occurrence 

 in our waters is insullicieut. 



