60 
SYNOPSIS OF THE FAMILY HETEROPYGII. 
tion in the waters of the cave where it is more abundant than in other 
places. The eggs were fully developed in these specimens, but no 
embryos could be detected. The fish is probably viviparous, and 
very likely gives birth to its young in October. 
Cliologaster Agassiz, Amer. Jour. Sci., xvi, p. 135, 1853. 
Eyes in normal position and well developed. 
Head with small granulations on the surface of the skin. (No 
papillary ridges.) 
Teeth minute, curved and arranged in rows on the intermaxillary 
and inferior maxillary bones. None on the palatines in the adults. 
(Of the four specimens examined, the two larger (O. cornutus') are 
without palatine teeth, while the single specimen of C. Agassizii, 
which is evidently a young fish, has a few minute teeth on the pala- 
tine bones. In the smallest specimen of C. cornutus the mouth is 
abnormal, the intermaxillaries being reduced to a small central portion 
and there are consequently no teeth in the upper jaw, but the minute 
teeth on the palatines are present.*) 
{Body without opercular papilla and papillary ridges on the sides.) 
Pyloric appendages two on each side. Stomach rounded and turned 
slightly on the side. 
Ovary situated principally behind the stomach. 
Fins. Ventrals absent. Dorsal, 8 or 9. Anal, 8 or 9. Pectoral, 12. 
Caudal, 28. 
This genus principally differs from Amblyopsis and Typhlichthys by 
the presence of eyes, the absence of papillary ridges on the head and 
body, by having two pyloric appendages on each side instead of 
one, and by the posterior position of the ovary. It agrees with Typh- 
lichthys in the absence of the ventrals, and the young further agree 
by the presence of palatine teeth. 
believe this is one of those interesting cases where one set of organs, or one 
portion of the animal structure, takes the place of another which from accident is 
wanting, and that in all probability these palatine teeth, that under normal con- 
ditions wmuld be cast otf as the fish attained maturity, would have continued to 
exist in tiiis specimen and answer all the purposes of the intermaxillary teeth. 
But that in this accidental continuance of these palatine teeth, from the mere 
mechanical use forced upon them, we have the first stages of the development of 
a distinct genus, to be characterized by permanent teeth on the palatines, and 
reduced upper jaw bones, as many of the developmental school would argue, I do 
not think will bear the test of facts observed. 
A not uncommon malformation of fishes consists in the entire or partial absence 
of the maxillary or intermaxillary bones. I have specially noticed this among our 
common fresh water trout (Salmo) and marine Conner or sea perch (Ctenolabrus) 
but there have never been recorded allied genera with these characters, while 
the malformed specimens are hardly numerous enough to give support to the the- 
ory that such malformations are hereditary, and it is probable that each case was 
caused by the non-development of the parts from special cause during embryonic 
life, or by accident to the individual. 
