1883.] NATURAL SCIENCES OF PHILADELPHIA. 133 



the Nearctic realm, only three of the above, Esox reticulatus, 

 Erirayzon sucetta and Anguilla rostrata, extending into the 

 Alleghanian district. Of the remaining eight species, four are 

 restricted to New Jersey, and in the case of two of them, Pceci- 

 lichthys erochrous and Mesogonistius chsetodon, the corresponding 

 parts of Delaware ; the other two species being Gliola chalybsea 

 and Amiurus prosthistius. Poecilichthys erochrous is the only 

 Etheostomine perch which inhabits muddy waters, though it is 

 not confined to such bottom, living as well in the gravelly but 

 dark brown-stained streams of the New Jersey pines. The 

 Amiurus is new to science, which is quite unexpected in the case 

 of so large a fish. Its characters are as follows : — 



Caudal fin rounded when expanded, not straight or slightly 

 concave, the marginal rays being shortened. Anal fin long, one 

 specimen with 27 rays, two with 25, and one with 24 rays. An- 

 terior dorsal fin a good deal nearer the end of the muzzle than to 

 the adipose fin. Length of head 2-66 times in length without 

 caudal fin ; depth at first anal ray 4:'25 times in same. Greatest 

 width of head just equal to depth of body at first anal ray. Eyes 

 small, the space between them five times their long diameter. 

 Pectoral spines a little larger than dorsal spines, with posterior 

 points onl}', which are stronger than those of the dorsal. Maxil- 

 lary barbel to near the middle of pectoral spine ; humeral process 

 little roughened, extending a little beyond middle of spine. Radii 

 D. I. 6 ; C. + 18 + ; Y. 8 ; P. I. 8. Color generally black ; the 

 under surface of the head silvery white, fading on the belly to 

 dull white and posteriorly pink, as far as base of anal fin. Fins 

 black, pectorals and ventrals pale at base. Total length m. 0-208 ; 

 from end of muzzle to base of dorsal spine, '042 ; to posterior 

 base of adipose fin '149; to base of caudal fin (end of ha?mapo- 

 physis) -no. Depth at first anal ray -039. Total length of a 

 larger specimen -233. 



When first seen the specimens of this species were supposed 

 to be unusually dark-colored examples of the common Ami- 

 urus nebulosus. A critical examination soon showed that they 

 diflGer in the important characters of the considerably more anterior 

 position of the dorsal fin, 4 to T more anal radii, and more rounded 

 outline of the caudal fin. He had compared it with the A. nebu- 

 losus from Lake George, N. Y., and from the Hudson and Dela- 

 ^ware Rivers. In fact its characters ally it to the western A. 

 natalis, from which it diflTers by its more slender form and more 

 rounded caudal fin. 



The following was ordered to be printed : — 



