422 Zoological Sociefij : — 



drica, decoUata vel truncato-obtusa ; anfractihus distinctis, vel 

 l<rvihtis vel transverse coslatis. Aperlura ova/is, hrevis ; peri- 

 tremale conliniio. Labrum simplex. Epidermis nulla. 

 Animal littorale, amphibium, sed revera marinum et branchiis 

 spirans. Infjrcdienti, discus fenninalis proboscidis pro pedis parte 

 antica servit ; itaque modo fere larvarum PhaUcnidarum Geome- 

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

 e plurihus anfractibus quam adult a constat; prioribus in plerisquc 

 demum {ut in lid. liulimo dccoUato) defractis, truncata cvadit. 



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

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

 continue<l 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 geneiic name of 

 Jlerpetomotra ; derived from its })eculiar manner of crawling. This 

 appellation I had since ]nirposed changing into Truncntellu, the very 

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

 his 'Ilistoire 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. Joum. v. 429. t. 19. f. 4. 



" Valuta denticuluta, Mont. {CarycMum Myosotis, Midland, 

 Com])l. de I'histoire de Drapard.), and Assiminia Grayana, Leach, 

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

 Having an op])ortunity of examining both in a living state in the 

 summer of ltS32, I was surprised to find manifest indications that 

 both were pulmoniferous, vvliich 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 breatlung of air unmixed with water. In 

 the other case I was not so successful, though the utmost jiainswere 

 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 branchife ; 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 MoUusca. This, perhaps, \vill 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 

 lamina;, the lower jtrojectiiig beyond the upper, and separated from 

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

 shaded with dnereous. 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 



