THE NAUTILUS. 133 



Dr. Gould's description agrees perfectly with his figure. 

 Both text and figure prove that his Placobranchus was a true 

 Elysia wdth lateral lobes not united dorsally. He says: 

 "Body ovate-lanceolate, the lateral expansions about two- 

 thirds its length and not quite meeting when reflected upon 

 the back." 



The species will stand thus : 



Genus Elysiella Verrill, 1872 : type 

 Elysiella. catula Verrill, 1872. 

 Elysiella pusilla Bergh, 1872. 



Genus Elysia : Elysia catula Gould {Placobranchus catulus 

 Gould, 1870). 



HELIX NEMOBALIS AT ENOXVILLE, TENNESSEE. 



BY T. D. A. COCKERELL. 



Mr. M. D. Barber has very kindly sent me a series of H. 

 nemoralis collected at Knoxville ; descendants of the Lexing- 

 ton, Va., colony, as explained by him in Nautilus, xxxi, p. 

 107. The specimens all have the yellow ground color (var. 

 lihellula), and sort out as follows: 



Adults. 



00000. 16, four of which are bimarginate (the dark peri- 



stome bordered inwardly with a white rib). 



10345. 2, one having max. diam. 26 mm. 



12345. 21, of which five are bimarginate. 



123(45). 14, of which two are bimarginate; two have max. 

 diam. 25 mm. 



123,45. one. 



Immature. 



00000. 16. 



12345. 15. Some would doubtless have become 123(45) 



on maturity, the formula being taken from 

 near the mouth. 



123(45). six (var. reaumuria Moq.). 



(12)3(45). three. 



10345. two (var. argenvillea Moq.). 



