CAVE FISHES OF NORTH AMERICA. 



383 



brancs joined to the isthiiiiis, .somotiincs loosely; bod}' covered with 

 veiy small, irregularly arranged cycloid scales; no lateral line; vent 

 in the j^oung located in the normal position, but in the adult far for- 



CuT 8. — Internal anatomy of Amhli/opsis spelwufi. 1, anus; 2, opening of the oviduct; 3, oviduct; 

 4, ovary, which is single; 5, liver; 6, duodenum; 7, gall-sac; 8, pectoral fin; 9, one of the pyloric 

 cceca; 10, ccecum; 11, stomach; 12, spleen; 13, air-bladder; 14andl6, intestine; 15, pancreas; L, liver. 



ward, just behind the angle of the union of the gill membranes. The 

 transition of the vent from what is its usual position in most fishes to 

 this unusual one just back of the gill openings takes place gradually 

 as the fish matures"; ventral fins wanting 

 Qfxcept in A/nhlr/opsis, very small in this 

 species; pectorals inserted rather high, mod- 

 erate in size; no spines in an}' of the fins; 

 dorsal and anal fins nearly opposite; caudal 

 rounded or even pointed at the tip; no 

 median crest on the cranium; stomach coecal, 

 with 2 to -i p3'loric cceca; air-bladder well de- 

 veloped; ovary alwa\^s single. Eggs caught 

 b}' the gills when spawned, at least in Amhlyopsis^ and held there 

 until hatched; young remain in the gills in A/nljli/oj^si's until about 

 four-tenths of an inch long.^ 



«In a specimen of Amblyopsis 1.26 inches long the anus is just below the insertion 

 of the j^ectorals. In a specimen 1 inch long it is nearer the ventrals than the pec- 

 torals. In a specimen of Ti/phlichthys 1.1 inch long the anus is well in front of the 

 pectorals, but a short distance behind the gill. — Eigenmann, Pop. Sci. Mo., LVI, 

 1900, 485. 



^ Eigenmann, Marine Biological Lectures, 1899, 313. 



Crx 9. — Alimentary canal of Trog- 

 Uchthys rosx. 



