LATIRUS. 87 



P. NODULOSA, A. Ad. Not figured. Australia. 



P. LucuLENTA, H. & A. Ad. White, with a broad flesh-colored 

 band in the middle of the nodosely plicate whorls, and with a 

 series of rufous-dotted spiral liri» at the fore-part of the last 

 whorl. Dimensions not given ; not figured. Gulf of Mexico. 



P. viBEX, Brod. Turrited, seven-varicose, varices subnodose, 

 transversely sulcate ; subluteus, aperture white, sulcate within ; 

 margin of labrum crenulate ; canal very short ; epidermis fus- 

 cous, rugose. Length, 1*63 inches, lat., 1 inch. 



St. Elena and Panama; sandy mud, six to twelve fathoms. 



" This shell appears to be intermediate between Murex and 

 Turhinella. It has the varices of the former, and the plaits on 

 the columella which distinguish the latter." 



Described as a Mu7'ex, and referred by Sowerb}^ to Pallia 

 (= Gantharus). Not figured. 



Genus LATIRUS, Montfort. 



As already stated in my synopsis of the genera, the diagnosis 

 of this genus is very unsatisfactory, its distinction from Peris- 

 ternia being entirely arbitrary. One of its characters is that the 

 shell is umbilicated, yet perhaps half of its species are utterly 

 without perforation, whilst those which possess it, show only a 

 narrow opening, except when abnormal in growth — like L. Ma- 

 derensis. Swainson's group Plicatella has been adopted by 

 Messrs. Adams as a subgenus of Latirua.^ having " spire moder- 

 ate, whorls angular, concavely depressed around the upper part," 

 but these are only comparative characters, and I prefer to sup- 

 press the group rather than place in it species having no relation 

 thereto, as Messrs. Adams have done. The umbilicus shows 

 more distinctly in most of the species of Latirus than in those 

 of Peristernia., but in some of them it is not any better marked ; 

 Latirus., however, differs in form from Peristernia^ the species 

 having longer spire and canal, the columella generally straight, 

 the plications more central, simply .because the canal is more 

 produced. 



The animals of most of the species that have been observed, 

 are of a dull red color. 



