300 rYKAMIDELLIDiE. 



penult turn is not particularly high ; the nucleus sinks 

 obliquely into the blunt apex. The body, which is about 

 equal to the spire in length, is slightly angulated at its 

 periphery, and declines rather abruptly, though convexly, 

 at its base. The mouth, which occupies from two-fifths to 

 only a third of the entire length, has an ovate-acute figure, 

 being rounded below where it is a little disposed to become 

 effuse, and sharply contracted above. The outer lip, 

 whose throat merely exhibits the traces of the external 

 sculpture, is simple and acute ; it is nearly straight above, 

 and abruptly arcuated anteriorly. The pillar lip is nearly 

 straight, and becomes broadly and flatly reflected near its 

 union with the opposite lip ; its fold is tolerablj^ distinct, 

 and lies rather above the middle of the inner lip. The 

 axis is more often imperforate ; there is sometimes, how- 

 ever, an umbilical crevice. The ordinary length of exam- 

 ples, is only the tenth of an inch ; the breadth, in general, 

 does not much exceed one-half this measurement. 



Mr. Jeffi-eys, in his valuable Catalogue of the British 

 Odostomia:, considers the Helix striata of authors to be the 

 fry of this species.* 



The animal, in examples which we have examined at 

 Brassay Sound in Zetland, is of a sulphur-yellow colour ; 

 its head is rather produced and rounded centrally, and 

 flanked by two obtuse subtriangular tentacula with eyes 

 placed at their inner bases ; the foot is oblong, bilobed in 

 front and obtusely angled, and terminates in an obtuse tail. 

 Mr. Clark describes sj)ecimens observed by him in June, 

 1850, at Exmouth, as " of a hyaline white, delicately 



* Walker, Test. Miniit. f. 29, from which Ilcliv striata, Mont. Test. Brit, 

 p. 44,5 ; Maton and Rack. Trans. Linn. Soc. vol. viii. p. 204 ; Turt. Conuli. 

 Diction, p. 57. — Turbo slrlatus, Flem. Brit. Anim. p. 300. — Ilissoa striata, 

 Brown, 111. Cciich. G. B., p. 12, pi. 9, f. 22. 



