1862. ] MR. LOVELL REEVE ON A NEW PHYSA. 105 
corresponding to the greater relative depth of the calcarine sulcus, 
exists in this brain, as in that of Lemur and Galago and all the true 
Apes. 
Me The brain of Stenops conforms closely with that of Lemur, both 
in its general form and the disposition of its surface-markings. The 
principal differences that were observed between them are described 
in the paper; and then follows a comparison of the brains of these 
two animals with those of the higher Quadrumana. As has been so 
well shown by M. Gratiolet, in his beautifully illustrated memoir 
upon this subject, a certain type both of general configuration and 
of surface-markings pervades the brain of all the Primates, from 
Man to the Marmoset. From this type M. Gratiolet excludes the 
Strepsirrhine Quadrumana, placing them, with the Insectivora, in a 
-group of Mammalia whose cerebral organization he considers to be 
quite distinct from that of the two first families of Quadrumana. 
The author of the present paper finds reason to dissent from this 
proposition, and upon cerebral characters alone would retain the 
Lemurs in the position assigned to them by the majority of systematic 
zoologists—admitting, however, that, while possessing certain very 
important points of structure peculiar to the Primates, they are in 
many respects, especially in the shortness of the posterior lobes, an 
aberrant group, forming a transition towards the Cheiroptera, Car- 
nivora, and other inferior Mammalia.” 
This paper will be published at full length in the Socicty’s 
‘ Transactions,’ and appropriately illustrated. 
The following paper was read :— 
ON A NEW FORM OF PuHYSA, OF THE SECTION AMERIA, RE- 
CEIVED FROM GrorGE FrencH ANnaGas, Esa., or ANGASTON, 
Sours AvustTrALis, CoRRESPONDING MEMBER OF THE So- 
ciety. By Loveuu Reeve, F.LS. 
The genus Physa occurs abundantly in the ponds and ditches of 
Europe and North America, and throughout the intertropical main- 
land and islands of the Eastern hemisphere. But in all the nume- 
rous species belonging to this wide range of geographical distribution 
the shell is regularly convex and smooth. In Australia and New 
Zealand a new type appears, in which the shoulder of the whorl is 
broadly angled. Eight species, in the collection of Mr. Cuming, 
characterized by this angular growth, some of them with the spire 
flatly immersed—two from New Zealand, the rest from North 
Australia, Port Essington, and the Boyne, Calliope, and Fitzroy 
Rivers—have been lately described by Mr. Henry Adams under the 
new generic title of Ameria, all being uniformly smooth. They differ 
from the rest of the Physe in being formed on the angular type; 
they resemble them in being still destitute of sculpture. The form 
of Physa now introduced from South Australia is of the angular 
type, but it differs from all others in being sculptured transversely 
with thread-like ridges. The shells of the allied genus Limnea are 
