65 



ripliory of the whorls is much larger, giving a suhangnlar aspect to the 

 wliorls : apex acute: spire with the outlines nearly rectilinear: 

 whorls five or six, rather convex, with a well impressed suture : ap- 

 erture long obovate : sinus small : canal wide and short. 



Mean divergence 40°. Length of spire .1 inch; total length .18 

 inch ; breadth .085 inch. 



Mangelta densestriata. Shell fusiform : white : with narrow 

 prominent ribs, ten or eleven on each whorl, and crowded regular 

 excessively fine deep spiral strite, which cover the entire surface and 

 are not interrupted in crossing the ribs : apex acute : spire with rath- 

 er convex outlines : whorls seven, subangular near the summit, with 

 a rather deep suture : last whorl long, and gradually attenuated into 

 a wide canal. 



Mean divergence 40^ ; length of spire .13 inch ; total length .28 

 inch ; breadth .11 inch. 



Mangelia muricoides. Shell fusiform and slender : pure white : 

 with six narrow subacute prominent ribs on each whorl, which are 

 sinuated posteriorly on the right side, and which are continuous along 

 the spire like a Murex ; with very numerous microscopic spiral striae 

 in the intercostal spaces : apex acute : spire with the outhnes nearly 

 rectilinear : whorls six, slightly convex, with a lightly impressed su- 

 ture : last whorl gradually attenuated below into a wide canal. 



Mean divergence 32° ; length of spire .09 inch; total length .18 

 inch ; breadth .07 inch. 



Maxgelia liicoNiCA. Shell biconic : whitish, with a narrow spi- 

 ral band of brown at the summit of the whorls, which is darker be- 

 tween the ribs, and a similar wider band a little anterior to the peri- 

 pliery of the last whorl ; (or some specimens may be described as pale 

 brown, with a spiral band of white on the periphery of the whorls, 

 and as white anteriorly) : with strong transverse rounded ribs, about 

 nine on each whorl, and excessively fine spiral rather distant raised 

 lines, which are obsolete on the summits of the ribs : apex acute : 

 spire with the outlines nearly rectilinear : whorls six, subangular, 

 with a moderately impressed suture : aperture narrow : labrum often 

 much thickened by the last rib : sinus near the upper extemity of the 

 labrum, rather large in old shells : canal short. 



Mean divergence 45° ; length of spire .08 inch ; total length .18 

 inch ; breadth .09 inch. 



Var. alha^ entirely of a pure white color. 



This species resembles P. symmetrica Rv. and Mangelia Dysoni Rv. 



