422 Zoological Society : — 



drica, decollata vel truncato-ohtusa ; anfractihus distinctis, vel 

 IcBvihtis vel transverse costatis. Apertura ovalis, brevis ; peri- 

 tremate continuo. Lahrum simplex. Epidermis nulla. 

 Animal littorale, amphihium, sed revera marinum et branchiis 

 spirans. Ingredienti, discus terminalis proboscidis pro pedis parte 

 antica servit; itaque modo fere larvarum Phalcenidarum Geome- 

 trarum gradibus alternis incedit. Testa junior, tereti-acuminata, 

 e pluribus anfractibus quam adulta constat; prioribus in plerisque 

 demum (ut in Hel. Bulimo decoUato) defractis, truncata evadit. 



"It is now nearly three years (1829) since the acquisition of a single 

 live specimen of Cyclostoma truncatulum, Drap., and a long and 

 continued observation of its animal, convinced me that it was entitled 

 to rank as a distinct genus from any which were then constituted. 

 I had accordingly designated it in my MSS. by the generic name of 

 Herpetometra ; derived from its peculiar manner of crawling. This 

 appellation I had since purposed changing into Truncatella, the very 

 name by which I find the self-same species designated by Risso in 

 his 'Histoire Nat. &c. de I'Europe Mcridionale.' In this work, 

 however, the genus rests, like very many others of the same writer, 

 on most unsubstantial ground, the animal being entirely neglected." 



"AssiMiNiA. Berkeley, Zool. Journ. v. 429. t. 19. f. 4. 



" Valuta denticulata, Mont. {Carychium Myosotis, Michaud, 

 Compl. de I'histoire de Drapard.), and Assiminia Grayana, Leach, 

 abound under stones in the salt marshes by the Thames at Gravesend. 

 Having an opportunity of examining both in a living state in the 

 summer of 1832, I was surprised to find manifest indications that 

 both were pulmoniferous, which were confirmed on a minute inspec- 

 tion of the internal structure, as far as perhaps could be expected in 

 such small animals. I was enabled in the former to trace distinctly 

 the course of the vessels, and was decidedly of opinion that the lungs 

 were constructed for the breathing of air unmixed with water. In 

 the other case I was not so successful, though the utmost pains were 

 taken ; but as the animal is only half the size, the difficulty was much 

 increased. I am enabled, however, to assert, that I could detect 

 nothing like branchiae ; and what is more to the point, that the vault 

 of the cavity of respiration was traversed by a multitude of minute 

 vessels all tending one way towards a large vessel running down in 

 the direction of the heart, which is exactly the structure in pulmo- 

 niferous Mollusca. This, perhaps, will be esteemed as decisive when 

 the external characters of the animal are taken into consideration." 



" Assiminia Grayana. 



" Foot broadly obovate, obtuse, composed evidently of two distinct 

 laminae, the lower projecting beyond the upper, and separated from 

 it by an accurately defined line ; above fuscous, beneath ohvaceous, 

 shaded with cinereous. Tentacula very short and obtuse, fuscous ; 

 eyes at the tips. Muzzle porrected, not truly proboscidiform, deeply 

 notched in front, fuscous, strongly annulated ; the edge of the lip 

 paler; on each side is a groove running backwards from the base of 



