CADUCIBRANCHIATA. 57 



sides. In the male the dorsal crest commences between 

 the shoulders; some sunk points upon the skin, chiefly 

 above ; these are openings of the glands which secrete a 

 lactescent, bitter and fetid humor." Duges. (39) 



2. Onychodactylus, Tschudi. 



Synonym, Dactylonyx. 



Vomerine teeth in a transverse, medially interrupted, 

 row behind the inner nares; sphenoidals wanting ? 

 tongue round, entire, free only at its borders ; skin smooth, 

 perforated with mucous pores; tail long, round, but dis- 

 tally compressed; digits distinct, four in front and five 

 behind, terminating above usually in a black nail-like 

 spot. 



The name of this genus, derived from dactylus nail 

 aid onyx finger, has reference to this last character- 

 istic ; but an interesting fact is that a similar spot is often 

 present in large Amblystoma, and it seems to be merely 

 incidental, varying with age and the seasons. 



