NATURAL SCIENCES OF PHILADELPHIA. 287 



Eye 2.33 times in front ; head short, contracted at the front, four times in 

 length ; canthus rostralis vertical concave ; brown, with many large oval 

 pale spots above only. C. varioltjs. 



III. Unossified margin of muzzle exceedingly narrow, no tentacles, D. I. 7. 



Head short, broad, 4.25 times in length ; eye 2.66 in front. Black, below 

 brown ; small. C. sericeus. 



The smallest of these species, it will be observed, has the most 

 complete dermo-ossification, and the largest the least. The next 

 largest species, G. tectirostris, is next most fully ossified, while 

 the G. malacops^ with but little ossification, is after G. sericeus, 

 and G. variolus the smallest. So there is no relation between the 

 ossification and the size. 



It may be observed that these species all agree in many points 

 not above mentioned, viz. : Anal radii V. ; V. I. 5 ; P. I. 6 ; and in 

 having the inferior lobe of the caudal longer than the superior. 

 Thorax and belly naked ; lateral lines 23-4. 



CH^ETOSTOMUS ALGA, Cope, sp. nov. 



Width of head 3.33 times in length without caudal. Preoper- 

 cular spines thirteen, of which two posterior are longer, and ex- 

 tend a little beyond the line of the orbit. Muzzle with numerous 

 tentacles on the margin and sides, and a Y-shaped series above of 

 larger size, the largest in front at the apex of the Y. Dorsal 

 spine a little longer than base of fin, one-half length ; pectoral 

 spine extending to basal third or two-fifths of ventral spine. 

 Scuta with ten serrate subequal ridges, each terminating in a spine. 

 The ossification of the derm forms only a narrow baud in front 

 of nares and orbit. 



Total length .165 m. I associate with this species a second 

 specimen, which agrees in every respeet except in wanting tenta- 

 cles. This is probably, as Giinther states of G. cin^hosus, the 

 female. 



This species is apparently near the latter species, but has a 

 shorter body. 



CH^TOSTOMUS MALACOPS, Cope, sp. nov. 



The lores are naked to near the nares, but the ossification ex- 

 tends in an angle to the middle of the muzzle. Width of head 



o' 



1872.] 



