SUPPLEMENT. 491 



Chilodontoidea, genus iiov. 



Shell short, thich, encycloicl, slightly pupgeform, imperforate. Whorls irregular, 

 the anterior ones carinale ; hody-ivhorl considerably shorter than the spire; ornamen- 

 tation suhreticulate. Aperture externally quadrate and oblique, with a double callosity 

 on the columella, which is dentate at the angle ; a broad callosity inside the outer lip 

 further restricts the aperture internally. 



There are many points of resemblance between tliis curious genus and Chilo- 

 donta, Etallon, which, however, is represented as having five internal teeth or 

 callosities. The Corallian genus also has a more distinctly trochiform spire, 

 though the character of the ornamentation is somewhat similar. Fischer (' Manuel,' 

 p. 818) makes Chilodonta a sub-genus of Clanculus, one of the Trochidse. In this 

 connection the following references may be useful. 



Chilodonta clathrata, Etallon. Corallien du Haut Jura ii, p. 54. 



Trochus [Monodonta) clathratus, Etallon. Zittel, Gast. Stramb. Schicht, p. 329, 

 pi. xlviii, figs. 27 and 28. 



Chilodonta clathrata, Etallon. De Loriol, Mem. Soc Pal. Suisse, vol. xvii 

 (1890), p. 147, pi. xvi, fig. 15. 



454. OHir.ODONToiDEA ooLiTiCA, sp. uov. Plate XLIII, figs. 19^ 20 a, 20b. 



Description : 



Height . . . . .9 mm. 



Body- whorl to total height . . . 35:100. 



Spiral angle irregular and convex. 



The apex is sharp ; number of whorls eight, flat to subconvex in the early 

 stages, strongly carinate in the later ones, and separated by a deep suture. The 

 ornaments in the upper part of the whorls consist mainly of delicate and rather 

 sinuous axial lines, which on the keels produce a fine granulation ; in the anterior 

 portion of the whorls the ornaments are chiefly spiral. The shell gapes somewhat 

 between the penult and body-whorl, which latter is stumpy, and towards the 

 aperture its upper margin encroaches on the penult. The body-whorl is carinate 

 and spirally ornamented on the base. There are, however, considerable differences 

 in ornamentation according to locality. 



The characters of the aperture are those of the genus. 



Relations and Distribution. — The distinction between this form and Chilodonta 



