STATE GEOLOGIST. 89 



posterior margin nearly tlie segment ofa, circle, armed with numer- 

 ous very long unequal spines which extend only about half the 

 hight, being replaced by short close hairs; the anal opening is very 

 high; the terminal claws are long, straightish, and have a small 

 thorn near the base. 



The males are smaller than the females, and the abdomen is less 

 broad; the antennules are longer than the beak and furnished with 

 ^ flagellum. The sexual period occurs in September or irregularly. 

 This species has only been encountered once, during September, in 

 Poplar river, Cullman county, Alabama. 



Sp. 2. lieydigia acantliocercoides, Fischer. 



Lynceus aca,nthocercoid6s. fischer, leydig. 

 Eurycercue acanthocercoides, schoedleb. 

 Alona acanthocercoides, p. ts. mukller. 

 Leydigia acanthocercoides, kurz. 

 Leydigia quadrangtdarls, herkick. 



This species, reported in a previous paper, is, as was said, nearest 

 like L. acanthocercoides; and I am now able to verify the very in- 

 <;onspicuous differences upon which the two are separated. Our 

 specimens of the L. quadrangularis have the pigment fleck fully as 

 large as the eye, Kurz to the contrary notwithstanding, and the 

 claw of the post-abdomen is present, while in the present species 

 the pigment fleck is much larger and furnished with lenses; the 

 spine of the claw is wanting; the labrum is densely hairy; the abdo- 

 men is narrower, and the shell higher. The shell is very obviously 

 striped in the posterior portion. The anus is higher than in the 

 previous species. In other respects the two seem alike. 



V. — GEifus Graptoleberis, Sars. 



A genus containing two closely allied species, having some affinities 

 with Alonella. The shell is entirely reticulated, and there is a sort 

 of crest along the back; while, on the other hand, the head is flat- 

 tened and rounded in front. There can hardly be said to be a beak. 

 Seen from above, the animal resembles some species of Alonella, 

 but the head is larger proportionally and more horizontal. The 

 lower posterior angle is spined. The antennae have seven setae and 

 are very long, in this respect resembling Camptocercus. The dorsal 

 -contour is not greatly arched. The post-abdomen has short claws 

 and anal bristles, but no teeth. 



