﻿3^4 AXODONTA 



\ on Martens, (1. c), considers il to be probably the same as 

 J. clialcoen^is Crosse and Fischer. 



Hannibal, (1. c), considers it a variety of cygiiea and refers 

 to it as synonyms, ./. niittalliana Lea, icahlametensis Lea, 

 coarctata Anton, califoruicnsis Lea, chapalensis Crosse and 

 Fischer, cxilior Lea, and chalcocnsis Crosse and Fisclier. I lis 

 figures cited above are from Californian si)ecimens and he 

 does not ai)pear to have had any Mexican specimens for com- 

 parison. 



Croup of .liiodoiifa dejecta. 



Shell rather solid, subtrapezoidal, narrower and rounded in 

 front, where it is often considerably thickened, with a slight 

 post-dorsal wing ; beaks compressed, the sculpture consisting 

 of numerous irregular ridges, which have a tendency to become 

 doubly looped and nodulous ; epidermis smoothish and shining, 

 greenish or ashy-brown; nacre lurid, darker in the cavity of 

 the beaks ; muscle scars irregular, not well defined ; dorsal 

 scars few and rather deep. 



Animal having the branchiae dark colored, the inner wider 

 in front, nearly or quite free from the abdominal sac, the outer 

 wrinkled on the outside into longitudinal and vertical folds, 

 all four united to the mantle to the extreme posterior end", 

 palpi very large; mantle with a wide, thickened double edge; 

 branchial opening with numerous papilUe : anal opening 

 smooth ; su]>eranal opening long, deep, united a long way be- 

 low. 



Anodonta dejecta Lewis. 



Shell long, rhomboid or trapezoid, subinflated, strong, with 

 a well-develoj)ed, rounded ])osterior ridge, inequilateral ; beaks 

 low, widely spread in the adult but rather fiat, their sculpture 

 consisting of irregular, concentric, corrugated folds, often 

 extending well over the umbonal region ; greatest diameter of 

 the shell at or behind the middle ; in front of the posterior 

 ridge there is often a wide, shallow, radial depression, and 

 viewed from above the front end of the shell is wedge-shaped ; 

 anterior end narrowed, sometimes drawn out a little but al- 



