4o2 PYKAMIDELLID^E. 



the Chemnitzia, wliich are not seen in the fully adult E. 

 polita. 



With respect to the tentacula, we may state, that in all the 

 young E. polita, under half an inch in length, they are quite 

 white and the arcuated yellow lines in front of the foot are 

 wanting ; they are also flatter, with rudimental flake tips j but 

 with age all these young incidents disappear. All the Eulimas 

 are more or less distorted or arcuated posteriorly, but increase 

 of growth diminishes the effect of what is so apparent in the 

 young shell. 



The operculigerous lobes of the animal are as unequal as in 

 E. polita. The foot of this minute example appears propor- 

 tionately more slender and hyaline than in the adult ; it has 

 a labium well separated from its upper skin, which some 

 authors call a mentum ; but, even admitting that term, the 

 organ is very different from that continuous neck-production 

 in the ChemrutxuK, which we have styled a rostrum, and M. 

 Loven the mentum. 



The animal is extremely free and vivacious ; it delights in 

 swimming, and marches with far more celerity than the adult 

 E. polita. Axis of the specimen examined -^, diameter ^ 

 uncise. It is found plentifully in company with the E. polita, 

 and that variation termed E. nitida by the Scotch naturalists, 

 in the coralline zone at Exmouth, and off Teignmouth, in a 

 fine muddy and shelly bottom, in 14 fathoms water. 



The following have not occurred to me alive : 



E. SUBULATA, Donovan. 

 E. subulata, Brit. Moll. iii. p. 235, pi. 92. f. 7, 8. 



E. BILINEATA, Alder. 

 E. bilineata, Brit. Moll. iii. p. 237, pi. 92. f. 9 ; (animal) pi. K.K. f. 5. 



We believe that the latter is the young of the former. 



ACLIS, Loven. 



This genus contains only two very rare British species, the 

 Turbo ascaris of Turton and the A. supranitida of S. Wood ; 



