5100 Mollusks. 



Comparee, le genre et le nom furent adoptes par M. Lamarck (An. 

 sans Vert. p. 96) et par M, Bosc (Hist. Nat. des Coquilles, iii. 240) 

 mais il est singulier que ces deux savans naturalistes n'aient cite que 

 des especes etrangeres, comme des TenerifFe et des Maldives, tandis 

 qu'il y en a une ties abundatite dans nos provinces raeridionales. 

 C'est ce qu'a fait connoitre M. Fame Biguet observateur zele et 

 habile, residant a Crest, departement de la Drome (' Voyer le Bulletin 

 des Sciences,' No. 61, pour Germinal an X). C'est d'apres lui qu'en 

 a parle Draparnaud dans son c Tableau des Mollusques de la France,' 

 p. 99: et c'est egalement a sa generosite que je dois le plus grande 

 nombre des individus que j'ai ete a meme d'examiner ; je m'em- 

 presse de lui en temoigner ici mon vive reconnoissance." 



During the last few years this genus has received great attention 

 from various Englishmen, — from Mr. Baker, of Stamford Hill ; from 

 Mr. Lukis, of Guernsey ; and particularly from Mr. G. W. Sovverby, 

 of London, to whom zoologists are considerably indebted ; the latter 

 gentleman having established a new British species, T. Scutulum. 

 (See Loudon's Mag. Nat. Hist. vi. 45, and vii. 224). 



In the collection in the British Museum the family of the Testacel- 

 lidaj is placed after the Cryptellidae and before Plectrophorus. 



Testacellae live for the most part under ground, sometimes at the 

 depth of three feet. During fine weather, however, they may be 

 found near and upon the surface. They are rapacious, feeding upon 

 worms, which they swallow head foremost, and gradually draw in as 

 digestion proceeds. (Encylop. Metrop. tit. " Testacella"). As a 

 general rule members of this genus do not hybernate, although during 

 cold weather they are in an almost torpid state. (Loudon's Mag. 

 Nat. Hist. vi. 228). 



Generic Characters. (Cuv. iii. 39). * 



Animal elongated, slug-like, cylindriform, acuminated at each 

 extremity ; no cuirass ; head distinct, furnished with four intractile 

 tentacles, of which the posterior are the longest and carry the eyes 

 on the tips; foot long and rather indistinct, but extends on each side 

 beyond the body ; pulmonary aperture round, and, being dependent 

 on the protecting shell, is situate at the posterior fourth of the ani- 

 mal's length ; the orifice being placed entirely backwards, under the 

 right side of the aptfof the shell, the anal aperture is very qgar it; 

 organs of generation united, and showing their orifice near and behind 

 the great right tentacle. From the maimer in which the blood is 



