LAND AND FRESHWATER MOLLUSCA 
OF 
Here Nie Be aloe 
Part IV._OCTOBER 18863. 
(Plates XXII.-XLILI.) 
Havine given in Part III. the history and original descriptions of 
Benson’s Genus Macrochlamys and denoted the type M. indica, I 
shall commence this Part with a detailed description of that species 
and its anatomy, together with some other allied forms, and show 
what modifications and divergences they present. 
Stoliczka, when treating of this genus in the J. A. 8. B. 1871, 
p. 246, considers M. indica, Bs., of Calcutta, to be the type, for similar 
reasons as I have given. Professor C. Semper’s work is referred 
to, which leaves no doubt but that the species the latter received 
from Dr. J. Anderson and described was a true Macrochlamys 
from Darjiling, but not splendens of the N.W. Himalaya, which, 
from what I can remember of the animal, is a very distinct and 
different form. Stoliczka, unfortunately, instead of taking one of 
the Calcutta species for his detailed description of the genus, 
selected M. honesta, so different—-he says (p. 250) he could not 
detect the kale-sac—that to it he attaches a subgeneric value, being 
led to do so by observing the presence of the peculiar spermatophore, 
which he had not then made out to be that organ. Taking this 
character and the large lobes of the mantle, he considered Blanford’s 
Durgella its probable subgeneric position ; he says :—‘‘ This name 
has been proposed for Benson’s Heliv levicula from Tenasserim as 
type, and would indicate a close relation, both in the form of the 
shell and the characters of the animal, to Helicarion.”’ I have 
since shown, when describing the animal of Durgella levicula (Proc. 
Linn. Soc., Zool. xv. p. 291), how very distinct and how far removed it 
is in every way from the genus under review and Helicarion, 7. e. the 
Indian forms of this genus. The absence of an amatorial organ in the 
specimens of M. honesta dissected by Stoliczka is a departure from 
the typical form of Macrochlamys; and I shall treat of this point 
when describing that species. To show to what extent the true 
Helicarion of Australia differs from our Indian forms I give a Plate 
of a species kindly sent me from Sydney by Dr. 'T. Cox, for which 
I am greatly indebted to him. 
There are certainly three species in Calcutta that have been 
included under M. vitrinoides. Stoliczka alludes to two (J. A. 
S. B. 1871, p. 246) in these words :—‘ There occur two allied 
PART IY. ie 
