VOLUTION. 73 



Y. CAPITELLUM, Linn. PL 19, fig. 25 ; PI. 21, fig. 24. 



Yellowish white, or light brown. Length, 2-3 inches. 



West Indies. 

 V. mitis, Lam. (fig. 25), is a depauperate shell, not adult. 



Y. GLOBULUS, Lam. PI. 21, fig. 17. 



Yellowish brown, the revolving ribs whitish ; interior of 

 aperture and columella flesh-pink. Length, 1*25-1'75 inches. 



W. Africa; West Indies. 



Family YOLUTID^. 



The shells of this family are conspicuous and showy, and 

 many of them rare; like the Cypraeidse and Conidae, the acqui- 

 sition of fine collections is frequently deemed worthy the 

 expenditure of much time and money, and information upon the 

 classification and determination of the species is eagerly sought. 

 The consequences of this state of things are a large number of 

 so-called species erected out of mere individual variations and a 

 succession of classifications, each vying with the other in com- 

 plexity. Neither the anatomy of the animals nor the differences 

 between the shells justify the numerous generic divisions which 

 have been proposed, and I gladly follow one of the latest as well 

 as the most judicious of systematists, Mr. H. Crosse, in reducing 

 most of them to mere groups within the genus Voluta. H. and 

 A. Adams included a classification of Yolutidse in their " Genera 

 of Recent Mollusca," Yol. 1, 1853. They were shortly followed 

 by Dr. J. E. Gray, in " Zool. Proceedings," 1855, " Catalogue of 

 the British Museum," xxvii, 1855, and " Guide to the Mollusca," 

 1857. The latter was partially adopted, and partially adapted 

 to their former system by Messrs. Adams, in the "Appendix" 

 to their work, published in 1858. Crosse's arrangement of the 

 Volutes was published in "Journal de Conchyliologie," 3 ser. vi, 

 105, 1866; and xi, 263, 1871. Finally, Mr. Wm. M. Gabb 

 published a modified version of Dr. Gray's system, including, 

 however, the fossil genera, omitted by his predecessors. (Proc. 

 Philad. Acad., 286, 1876.) 



Two subfamilies have been made by Gray, Gill and others, 

 based primarily upon differences in the lingual dentition. One 

 of them, containing the genera Arnoria and Volutimitra of Gray, 

 10 



