160 
with certainty. Its colour is of a rosy white, and yellow in the cen- 
tre. It is possible that the N. Entrecastauzi may prove only an 
oboval variety, with a marginal summit of N. tessellata. When I 
shall have seen a greater number of specimens with their opercula 
I may be enabled to pronounce with more certainty. 
It results from this examination of the Navicelle collected by Mr. 
Cuming, together with those I have had an opportunity of studying 
up to the present time—lst, that the number of known species of 
this genus amounts at present to eighteen; 2ndly, that the Asiatic 
Islands is that part of the world which contains the greater number 
of species; and 3rdly, that Polynesia is afterwards the most rich 
locality in species of this genus. 
A communication by Mr. Lovell Reeve, “‘ On the genus Phorus, a 
group of agglutinating Mollusks of the family Turbinacea,” was then 
read. 
“Tt is remarkable that a group of mollusks of such decided import- 
ance as those which I have selected for consideration should have so 
long escaped the especial notice of conchologists. The genus Phorus 
was introduced many years since by De Montford; but as it was not 
recognised by Lamarck, few authors thought it worthy of adoption. 
Little enough is known of the nature or anatomy of the Phori, but 
the remarkable character which their sheils exhibit may be suffi- 
ciently estimated to rest their claim upon that alone to the rank of a 
enus. 
ett The character here alluded to is a property which these mollusks 
possess of agglutinating to the outer surface of their shells any frag- 
ments of stones, shells, corals, or other marine debris that they may 
chance to be in contact with, and which become so firmly attached 
that they cannot be dislodged without violence. The well-known 
Carrier Trochus (Trochus agglutinans, Lamarck; Phorus onustus, 
mihi) was for a long time the only species of Phorus known; when 
others even were discovered they were only regarded as varieties of 
that species, and the agglutinating property which they showed their 
animal occupants to possess, was not considered to be of any generic 
importance. The distinction however which De Montford assigned 
to these animals has become of infinite value, for we now possess 
’ several species of them, and the agglutinating power operates in dif- 
ferent ways in each; some shells, for example, are found with only 
a few small pebbles agglutinated to the earlier whorls, whilst others 
are characterized by their having only such fragments of shells or 
stones as are flat or tile-shaped collected round the edge or peri- 
phery of the whorls ; and these several methods of agglutinating are 
each confined to particular species. Other modifications of this pro- 
perty may yet be discovered, and I trust, as the Phori are not un- 
common in the West Indies, that they will ere long be made the 
subject of anatomical examination. 
‘««T see no reason at present for altering the situation which is com- 
monly assigned to these mollusks in the general system; the struc- 
