MACDON 
77 
point, Na Viti Levu, Feejee group ; and several specimens were selected for examination 
The tentacula are stout, conical, and closely approximated above the mouth, with n loivn- 
tudinal groove on their inner surface, and a somewhat sunken eye in a slight elevation 01 
gibbosity at the outer side, near the base. 
" The animal is furnished with a retractile proboscis of considerable length ; and when 
retracted, the external aperture is quite round and so small as to be scarcely perceptible. 
The anterior border of the foot is dilaminated, the plates or lips being separated by a deep 
transverse recess, which appears to have some communication with the sinus of the foot. 
The creeping-disk or mesopodium is well developed, and the lateral borders, which are 
produced into a simple lobe, are probably confluent with the epipodia. Its posterior ex- 
tremity is very thin, but rounded, and surmounted by the metapodium, which is a sub 
cylindrical mass of muscular fibres, continuous with those of the great retractor, and 
abruptly truncated posteriorly, where it presents a subcentral recess, which lodges the 
internally produced nucleus of the paucispiral operculum. 
" The oral teeth form a narrow circular band consisting of a pavement of sharp dental 
cells, whose points, as in other cases, are directed forwards. 
"The lingual pavement is small, but elongated in form and divided into two lateral 
arese, supporting several series of long and gracefully curved uncinate teeth, which seem 
to decrease in length from within towards the lateral borders of the membrane, where they 
also become bifid in the vertical direction. 
" The auditory sacs are of comparatively large size, containing otoconia. 
" Torinia (Gray). The anatomical characters of this genus (distinguished by the 
peculiar gun-screw form of the operculum, so much resembling that of SUiquaria) agree 
in every essential particular with the foregoing. 
" Scalaria. From a critical examination of the anatomy of Scalaria, I have no hesi- 
tation in placing it in the same family with Solarium. Its principal characters are as 
follow : — Proboscis long, retractile, with stout muscular walls ; the oral aperture furnished 
with lateral plates, composed of small dental cells with their points directed forwards. 
Lingual membrane supporting a double pavement of tenaculiform teeth, rather stout, but 
still very similar to those of Solarium, and not, as has been supposed, like those of Bulla. 
Thus the outer teeth present one or two secondary prongs, while the inner remain simple. 
The eyes are placed at the outer side of the base of broadly conical tentacula; and the 
auditory sacs contain vibrating otoconia. 
" The foot is dilaminated in front, and in general configuration resembles that of Sola- 
rium" 
From the above facts I think it may be affirmed that it is a violation of the simplest 
anatomical principles to place Scalaria with the TurritelHdm, and Solarium with the 
Litorinida, the genera in both of which families, as now received, are otherwise hetero- 
geneous enough. 
The vermetiform character of the animal of Torinia on the one hand, and the peculiar 
structure of the operculum of Siliquaria on the other (so closely aping that of the former 
genus), afford some indication that both may belong to the same family. Moreover the 
groove in the outer Hp of Solarium would appear to represent the branchial slit of Sili- 
