RETU8A. 205 



K. TRUNCATULA Bfuguiere. PI. 21, figs. 11,12; pi. 23, figs. 62-64. 

 Shell forming a conical cylinder, narrow on the upper half, more 

 or less deeply constricted in the middle, and expanding on the lower 

 half; it is nearly opaque and glossy: sculpture — numerous longitu- 

 dinal striae or fluted ribs on the upper half; these are often sharp 

 at the apex, not so distinct in the middle of the shell, and usually 

 disappear towards the base, where they are replaced by lines of 

 growth; the spire is frequently striated across, like an Ammonite; 

 epidermis filmy ; color white ; spire involute, abruptly truncated, 

 and encircled by a narrow and solid rim or rounded keel; whorls 3 

 —4, gradually decreasing in size towards the center of the apex ; the 

 first or innermost whorl is globular ; suture deep ; mouth narrow for 

 more than half its length on the upper part, pear-shaped and very 

 wide at the base, which is rounded : outer lip gently curved and 

 folded inwards in the middle ; the upper part projects (sometimes 

 considerably) beyond the apex; outer corner rounded ; inner corner 

 receding and obliquely incurved ; inner lip slight, continuous with 

 the outer lip above, where it is folded a little over the apex, as well 

 as over the pillar, behind which it forms a small and narrow um- 

 bilical chink ; pillar short, thick, and flattened : fold tooth-like and 

 strong {Jeffr.). 

 Coad of Norway to the Canaries ; Mediterranean and Adriatic Seas. 



Bnlfa truncatula Brug., Encycl. Meth., p. 377, 1792. — Utriculus 

 truncatulus Jeffr., Brit. Conch., iv, p. 421, pi. 94, f. 2. — Sars, 

 Moll. Reg. Arct. Norv., p. 285, pi. 26, f 2 ; pi. 17, f. 18 (var. pe^/w- 

 cida). — Retusa truncatula BuQ., Dautz. & Dollf., Moll. Rouss., 

 i, p. 527, pi. 64, f. 12-14.— Bulla truncata Ad. (not Gmelin), Tr 

 Linn. Soc, v, p. 1, pi. 1, f. 1, 2. — Volvaria truncata J^rown, III. 

 Conch., G. B., Ed. 1, pi. 19, f. 17, 18. — Cylichna truncata Loven, 

 Ind. Moll. Skand., p. 42.— Forbes & Hanley, Hist. Brit. Moll., 

 iii, p. 510, pi. 114, f. 7, 8; pi. vv, f. 4 (animal).— Meyer & 

 MoBius, Fauna der Kieler Bucht, i, p. 87 (animal). — Bulla retusa 

 Maton &Rack., Descr. Cat. in Trans. Linn. Soc, viii, p. 128, 1804. 

 — Retusa ohtusa Brown, Pop. Encycl., ii, p. 78, pi. 17, f. 110. — 

 Volvaria pellucida Brown, 111. Conch. G. B. Edit. 1, p. 4, pi. 19, 

 f. 45, 46. — Utriculus truncatulus var. pyrifonnis Monts., Nom. Gen. 

 -e Spec, p. 50. 



