CEUCIBULUM. IIT 



character of the nuclear whorls. It is too much the custom 

 among collectors, and even among naturalists, to examine and 

 preserve onl}- Tvell-conditioned adult specimens. More may 

 often be learned from deformed and ' ugly ' shells ; and espe- 

 cially from series in all ages of development." — Philip C. 

 Carpenter. 



In preparing the following pages I have made use princi- 

 pally of: 



W. J. Broderip. Descriptions of some new Species of Calyp- 

 trseidfe. Trans. Zool. Soc. London, I, 3 colored plates. 1835. 



This is almost a monograph of the family. 



Lovell A. Reeve. Conchologia Iconica. Monographs of 

 Calj^ptrsea, Crepidula, Crucibulum, Trocbita. 1858. 



G. B. Sowerby. Thesanrus Conchyliorum. Monograph of 

 the family Calyptraeidse. 1883. 



J. E. Gray. Notes on the specimens of Calyptrseidse in Mr. 

 Cuming's Collection. Proc. Zool. Soc. London. 186T. 



Genus CRUCIBTJLTJM, Schum., ISlt. 



C. scuTELLATUM, Gray. PI. 31 , figs. 13-24 ; PI. 32, figs. 25-88 ; 

 PI. 33, figs. 39-43. 



Shell solid, chestnut-brown or pale, with brown rays, polished 

 and often darker colored within, rudely radiately ribbed, 

 coarsely latticed by concentric ribs, or smoother and closely 

 radiately striated. Length, 2-2*5 inches. 



West Coast of America from Chili to Mazatlan. 



Varies greatl}' in sculpture, height, etc., giving rise to many 

 synon3'ms. The type form has been described as C. imbricatum, 

 Brod. (fig. IT), and the synonymy embraces G. corrugatum, 

 Carp. (figs. 18, 19), C. rugosum, Lesson, C. dentatum, Menke, 

 C. costata, Menke, C. Cumingii^ Carp., C. e.xtinctorium, Sowb., 

 C. rude, Brod., C. gemmacsea^ Val., C. pectinatiim, Carp. (fig. 

 24), C. umbrella, Desh. (fig. 20) =^ depressed specimens, and 

 C. planata, Morch. G. concameratum, Reeve (figs. 21, 22), and 

 C. serratum, Brod. (fig. 23), are young shells. 



