110 Ml*. Jeffreys on British Mollusca. 



longer than the rest. There are a few of them also on the upper 

 edge of the operculigerous lobe. The veil is flexible (probably serving 

 the purpose of tentacles), and so transparent, that when it is extended 

 beyond the foot, the latter can be seen through it. Foot rounded in 

 front and pointed behind ; it is stout and large for the size of the 

 animal. Eyes two, very large in proportion, seated on the veil about 

 half-way between the anterior edge of the shell and the terminal lobes 

 of the veil ; they do not appear to be raised at all above the level of 

 the veil, and are not placed on peduncles or protuberances of any 

 kind. When the creature is withdrawn within its shell, the eyes 

 seem to reconnoitre you like a porter from a hall- window. Opercu- 

 lum very thin and paucispiral, with oblique striae, which radiate from 

 the suture and extend half-way across. I did not observe any other 

 appendages. The animal is at first shy ; but when undisturbed for 

 some time, it crawls freely and rapidly, like a snail, with its shell 

 edgewise in a perpendicular position and quite straight ; and it also 

 occasionally swims like the Rissoce and other Gasteropods. It seems 

 to be more comfortable near the sides of the watch-glass, for which 

 it makes at once after being replaced in the water. I observed several 

 specimens of different ages ; and all of them presented the same 

 appearance and habits. 



I believe it will thus be seen that it resembles no known moUusk. 

 It is true that the Bullidce have no tentacles, and that some of them 

 are furnished with eyes ; but I am not aware that any possess the 

 peculiar cilia which fringe the veil or anterior part of the head in this 

 animal. It is also certain that none have an operculum, — while the 

 shell, which is not an unimportant part of the animal, is totally dif- 

 ferent. I am also not aware of any recent marine generic analogue, 

 as far as the shell is concerned, though this has in every particular 

 the form of a freshwater Planorbis. As it is evidently not a 

 Skenea, the question is whether a new genus should be formed for 

 its reception. Captain Brown placed it in his genus Spira ; but as 

 one of the principal characters assigned by him to that genus is shell 

 " nearly globular or semi-oval," which is by no means applicable to 

 this species, and as Spira embraces a heterogeneous assemblage of mi- 

 nute and immature shells from Walker (viz. Helix glohosa^ tubulatay 

 and others), I do not think it can be properly retained there. With- 

 out, however, attempting to found a new genus, I believe the same 

 object will be attained (at least provisionally) by adopting the genus 

 Euomphalus of Sowerby, which, constituted for fossil shells of the 

 mountain limestone, seems to be exactly suited for the shell in ques- 

 tion. The generic characters given by Sowerby in his * Mineral 

 Conchology,' vol. i. p. 97, are as follows : " An involute compressed 

 univalve ; spire depressed on the upper part, beneath concave or 

 largely umbilicate. Aperture mostly angular." Having closely ob- 

 served the animal and turned my attention to the shell, I was struck 

 by the remarkable resemblance which it presented, although on a 

 very small scale, to the Euomphalus pentangulatus ; and a subse- 

 quent examination of other fossils, supposed to belong to the same 

 genus (although some of them do not fulfil the generic characters 



