38 COELOCENTRUM. 



C. TOMACELLA (Morelet). PL 12, figs. 6, 7; pi. 14, figs 21-25. 



Shell deeply rimate, swollen-turreted, rather thin, diapha- 

 nous, arcuately, very closely striate, somewhat silky in appear- 

 ance, brownish-corneous; spire strongly tapering upwards, 

 rather broadly truncate, suture impressed, lightly submargin- 

 ate-crenate, whorls remaining 14, subequal, a little convex, 

 the last a little receding under the penultimate, shortly free, 

 compressed-carinate at the back and base, having a thread-like 

 keel below the middle. Aperture suboblique, irregularly sub- 

 triangular-oval, pale fleshy- whitish inside ; peristome contin- 

 uous, narrowly expanded and a little reflexed throughout, 

 whitish; parietal margin sloping, forming an angle with the 

 spreading left margin. Foramen of the truncate spire mod- 

 erately large, perspective. 



Length 35, diam. scarcely 10 mm. ; aperture with peristome 

 6y 2 mm. long, 5% wide (F. & C.). 



Length 37, diam. 10 mm. (Morelet). 



Woods of Tabasco, and in the ruins of Palenque, State of 

 Chiapas (Morelet) ;oban, Guatemala (Sarg). 



CyUndrella tomacella MOREL., Testacea Novissima i, p. 10, 

 no. 11 (1849). PFR., Monogr. iii, p. 568; Conchyl. Cab. p. 36, 

 pi. 4, f. 19, 20. SOWERBY, Conch. Icon, xx, pi. 14, f. 124. 

 Ccelocentrum tomacella FISCH. & CROSSED Moll. Mex. i, p. 342, 

 pi. 15, f. 11. STREBEL, Beitrag iv, p. 58, pi. 6, f. 3. MARTENS/ 

 Biologia, p. 271. CyUndrella moreleti DESHAYES, in Fer. 

 Hist., ii, p. 227, pi. 164, f. 16-18 (1851). 



Excessively near C. clava Pfr., but according to Crosse & 

 Fischer more swollen, a little smaller and paler, with fewer 

 whorls and perceptibly finer striation. The more obese shape 

 is its chief distinctive character. A specimen before me, pi. 

 14, figs. 21-25, is corneous-whitish, with no brown tint, retains 

 13 whorls, and measures, length 33, diam. 9% mm. The in- 

 ternal pillar is strongly swollen below the middle within each 

 whorl, rather abruptly contracted below the swelling. It is 

 sculptured with widely and irregularly spaced lamellae and 

 some scattered granules representing dislocated and broken- 

 up lamellae. The free edges of the lamellae are irregularly and 

 more or less serrate (pi. 14, fig. 23). The external sculpture 



