* 
ae ee wy Fae 
* 
48 W. Stimpson on the so-called Melanians of N. America. 
across the rostrum and tentacles. Oviparous.” The main fact 
of importance here brought out is that the animal is oviparous; 
the statement that the eyes are never beyond the middle of the 
tentacle would have been better left out, as it might lead to the 
Beaton that they were pene placed near or at the 
which is never the case; the mistake with regard to the 
ont teeth is quite hetaeed. 2 as the: armature of the tongue was 
little understood at that tirae; and the other characters men- 
tioned (except the colors) are common to a large number of Ros- 
trifers, but the description is satisfactory as far as it goes. In 
his subsequent remarks in the same paper, Prof. H. considers 
Anculosa to be intermediate between Melania and Melanopsis, 
and to be distinct from Jflaniu yirginica in the small size and 
discoidal shape of its foot. But, though the foot may assume 
this shape when contracted in the act of adhering to a rock in 
a strong current, it is not dissimilar to that of — in 
its normal shape, though undoubtedly somewhat shorte 
the other hand, the approximation of Anculosa to Helanigitts is 
eestor: as the typical fresh-water forms of the latter group 
ave the foot prolonged anteriorly beyond the tip of 
the cian character never seen in the true Meenas 
The Melanopsis-group seems to be but little understood; so 
of os aay referred to it (the Clionelle),* as I have cease 
, are ee and closely allied to the Pleurotomide, 
Sagiiaris to Clava 
The next notice on mer structure of these animals occurs in 
Professor Baird’s translation of the “ pts, Encyelo- 
ia,” (New York, 1851), article Mollusca, vol. ii, p. 
the pen of Prof. Haldeman. In this work the Malaniide consti- 
tute the first family of the Ctenobranchiata, which is thus char- 
acterized: ‘The mantle is simple, without fringe or siphon ; the 
head ends in a short trunk, and the food is vegetable, chiefly 
decaying Alge.” The fami: y is made to include - Melania, Litto- 
rind, Planazis, Eulima, Paludina, Amnicola, Valvata | Ampulla- 
ria, Leptoxis, ‘Melanopsis, e and (doubtfally) Scalaria ; ° thus 
uniting Lamarck’s Mélaniens and Péristomiens, and adding a 
few genera from various one families. The rather comprehen- 
sive character of this “ family,” as understood by Prof. Haldeman, 
ms to depend upon the entirely unwarrantable dependence 
Seca upon the ornamentation of the mantle edge, as a character . 
yf importance for purposes of classification. But it must here 
9¢ remarked that this character, upon which Prof. H. so strongly 
nsists in all of his papers, is one of very slight importance, as 
er ce gt 
noides = 
inwome deg eae eae 
So 
