324 PROCEEDINGS OF THE ACADEMY OF [1896. 



38a. Cerion glans Thorndikei Maynard* Contr. to Sci., 1894, Vol. 2, p. 116, f. 34, 



b, c, d. 



Waterloo, Nassau, N. P. 



This variety, like the next is not trenchantly defined. 



38b. Cerion glans varium Bonnet.* Rev. et Mag. Zool., XVI, 1864, p. 71, t. 6. 

 P. zebra Weinland, Sowb., Conch. Icon , pi. 2, f. 12 a, b. (1875). 



New Providence. 



Under this head may be grouped the mottled and maculated forms 

 with comparatively delicate, narrow riblets. Intergradation with 

 the maculated forms with slightly stronger ribs, such as " cinerea 

 mutata," "Curtisii," "cinerea tracta," etc., of Maynard, may be 

 expected. Gods and men may well stand aghast at the splitting of 

 C. glans recorded above. 



C. griseum is doubtfully distinct from glans. We leave it separ- 

 ate, because in the average, the two are distinguishable, and they 

 inhabit different islands. 



39. Cerion martinianum Kuster.* Conchyl. Cab., p. 75, t. 11, f. 3, 4. 

 Habitat ? 



40. Cerion Blandi Pils. & Van.* PI. XI, fig. 7. 

 Turks Island. 



Group of C. Agassizii. 



41. Cerion Agassizii Dall.* Bui. Mus. Comp. Zool., 1894, Vol. XXV, p. 120. 

 Nassau Ridge, New Providence, fossil in the calcareous sand-rock. 



42. Cerion Eleutherae P. & V.* PI. XI, figs. 19, 20. 

 Eleuthera. 



43. Cerion gubernatorium Crosse.* Journ. Conch., 1869, p. 186 ; Journ. Conch., 

 1870, t. 2, f. 4, lower figure. 



New Providence, Bahamas. 



Group of C. crassilahre. 



44. Cerion rude Pfr.« Malak. Bl., II, 1855, p. 102, t. 5, f. 1, 2. 

 St. Croix. A quaternary fossil. 



46. Cerion Yumaense P. & V.* Proc. A. N. S., 1895, May 4, p. 210. 



S.ferruginea Maynard, Contrib. to Sci., 1896, Vol. Ill, p. 19-21. 



Yuma River, Hayti. 

 46. Cerion crassilabre Shuttlew.* Sowb., Conch. Icon., 20, t. 2, f. 14. 



Porto Rico, Virgin Is. 



The locality given by Sowerby, " India " is a mistake. Porto 

 Rico may be considered the type locality, for here large specimens 



