132 FUSID@. 
produced; canal exserted ; columella obscurely plicate. Oper- 
culum irregularly ovate; apex obtuse; nucleus inconspicuous. 
The dentition of this mollusk appears to relate it somewhat 
to Ptychatractus, and I prefer to place it in the same subfamily 
with that shell, rather than make a new family for it. Norman 
shows that Meyeria is preoccupied by M’Coy for a genus of 
fossil crustaceans, and he therefore proposes the generic name 
Metzgeria; but I see no advantage (and much disadvantage) in 
changing names because they happen to have been previously 
used in some other department of zoology. 
SuspraMiLty PERISTEHRITINA. 
PERISTERNIA, Morch. 
Distr.—30 sp. Polynesia, Philippines, Australia, Indian 
Ocean, Zanzibar, Mauritius. P. nassatula, Lam. (xlviii, 93). 
P. incarnata, Desh., var. (xlviii, 94). P. Belcheri, Rve. ‘ xlviii, 96). 
Shell turreted, not umbilicated; whorls longitudinally ribbed ; 
aperture oval; canal moderate and recurved; outer lip thin and 
crenulated ; columella with one or two slight plaits anteriorly. 
The want of umbilicus, less distinct columella folds and recurved 
canal are the principal (and not sufficient) distinction from 
Latirus. 
Latirus, Montfort. 
Syn.—Chascax, Watson. Polygona, Schum., 1817. Plicatella, 
Swains. 
Distr.—34 sp. Polynesia, Philippines, Australia, Indian Ocean, 
Panama, W. Indies, Madeira. L. infundibulum, Ginel. (xviii, 95). 
Shell turreted, fusiform, sometimes umbilicated ; spire pro- 
duced; whorls nodulous, aperture oval-oblong ; outer lip thin, 
crenulated; columella straight, with two or three small oblique 
plaits in front. Mr. H. Crosse remarks upon the insufficiency of 
the diagnosis of Latirus by Montfort and H. and A. Adams, and 
proposes to relegate the species to Turbinella; that genus, how- 
ever, may be more advantageously restricted to the forms for 
which the genera Vasum and Mazza have been constituted. 
Swainson’s group Plicatella has been adopted by Messrs. 
Adams as a subgenus of Latirus, having “spire moderate, 
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, 
