EASTERN PROVINCE — SOUTHERN REGION SPECIES. 



413 



I 



Cylindrella jejuna, Gould. 



Shell ratber small, fusiform, truncated at apex, quite solid, of a pale 

 horii-color, longitudinally striped with delicate, white fig. 453. 

 lines ; spire composed of about 9 whorls, though when 

 entire the whole number would be about twice as many; 

 they are convex and separated by a well-marked suture; 

 the liist whorl has a delicate carina and extends in a 

 short necli ; the iipertuie is bell-shaped ; the peristome CyiindreUn jejuna. 

 white, continuous, and not in contact with the preceding whorl ; axis 

 simi)le. Length, 10""" ; breadth about 2i""". 



CyliDdreVa Jejuna, Gould. Pmc. Bost. Soc. Nat. Hist., iii, 41, Juue, 1848; Terr. Moll., 

 ii. :UU, pi. Ixix, liy. :{.— W. G. Binm:y, T. M., iv, 150; v, 383; L. & Fr.-W. 

 Sh., i, 23 (18()'J). 



CtjlindieJIa faiicgnia, Pfeiffe]!, part, Mai. Bliltt., ii, 13. 



Gonfjjjlosioma jejuna, Tkyon, Am. Joiiru. Coiicli., iii, 312 (18G8). 



Found abundantly in the Florida Subregion, near the mouth of the 

 Miami Itiver. 



SPUEIOUS SPECIES OF CYLINDRELLA. 



CiilindrdJa pontificK, Gox'ld, is Macroceramus i)ontificus, Pfk. 



Ci/liiirlrdla doldfun'-i ami lUieiiieri are species of HvJosjjira. 



CytindieUa caiiqianulata of Terr. Moll. U. S., i, 109, is uuknown to me. 



Fig. 454. 



MACROCERAMUS, Gould. 



Animal as in Cylindrdla {q. v.). See also below under M. poritijicns. 



Shell turreted or lengthened conic, rimate; whorls 9-15, gradually 

 increasing, the last often angular; aperture round, short, columella 

 usually plicate; peristome expanded, its margins subequal, subparal- 

 lel, not continuous, the external arched, the columellar dilated, re- 

 flected. 



Jaw thin, almost membranous, semi-transparent, light horn colored, 

 strongly arched, ends acuminated; cutting margin 

 without median projection ; anterior surface with num- 

 erous delicate, separated ribs, denticulating both mar- 

 gins ; these ribs run obliquely towards the median line 

 of the jaw, so that the central ribs meet before reaching 

 the lo^er margin of the jaw, forming an upper median 

 triangular space between the ribs. It was formerly 

 considered that this jaw was actually in separate pieces, 

 whose overlapping margins formed the ribs upon the 

 anterior surface (see Fig. 454). More careful examina- *^^ "(BianT)"" "*" 

 tion, however, has preyed the jaw to b« in one single piece, with 



