174 CERION. 



Family CERIONIDxE. 

 Characters those of the following genus. 



Genus CERION Bolten ' Morch, 1852. 



Cerion BOLTEN, Museum Boltenianum p. 90, 1798, in part, un- 

 defined MOERCH, Catal. Yoldi, p. 33, uva the first species (18.52). 

 DALL, Bull. Mus. Comp. Zool. xxv, no. 9, p. 120. PILSBRY & 

 VANATTA Proc. Acad. Nat. Sci., Phila., 1896, pp. 315-329. Stro- 

 phia ALBERS, Die Hel., 1850, p. 202. Not Strophia Meigen, 1832. 

 Cochlodon SowERBY, Tankerville Catalogue, p. 40, 1825, in part. 



Shell solid, cretaceous, cylindric or ovate, conic above, rimate or 

 perforate, composed of 8 to 13 compactly coiled whorls, the central 

 axis slender, hollow above, usually solid below ; apex entire. 

 Aperture ovate, vertical, the lip usually expanded or reflexed. A 

 spiral columellar fold and a parietal tooth usually are present in 

 recent species. 



Lung macroscopically plain except for the pulmonary vein. 

 Kidney oblong, with large cavity, and excreting apparently by a 

 secondary ureter. Genital system having a wide atrium, short penis 

 with terminal retractor, the epiphcdlus entering near or below the 

 middle of the penis sac. Vas deferens extremely long. Spermatheca 

 on a long duct which bears a long diverticulum. A vaginal retractor 

 arises from the right tentacular muscle. Free retractor muscles 

 independent to their posterior ends except the right tentacular and 

 tail retractors, which are shortly united. Jaw smooth. Teeth of 

 the normal type in Holopoda, the ectocones developed. External 

 anatomy as in Holopoda generally ; the labial processes well 

 developed. 



Type 0. uva (L.). Distribution, the Antilles, near the sea. 

 They live on bushes or other herbage, rarely retreating under stones. 



Cerion, from the Greek word kerion, honey-comb, alludes to the 

 resemblance of the spire to an old-fashioned bee-hive. 



The genus Cerion, or as it is commonly known, Strophia, is one of 

 the most characteristic forms of West Indian land-molluscan life. 

 With two exceptions, the species are all insular ; C. incanum and C. 

 antonii only, the former from the Florida Keys and perhaps the ad- 

 jacent mainland, the latter reported to be from Guiana, are conti- 

 nental. The Greater Antilles Cuba, Hayti and Porto Rico, with 

 the Virgin Islands and the entire group of the Bahamas, are inhabited 



