Mr. W. H. Benson on Freshwater Shells from India. 257 
third cells oblong, the fourth extending to the apex of the wing. 
Legs simple, elongate ; the tibie armed with two short spines at 
their apex. 
. Cladomacra macropus. 
C. nigra; capite, thorace, abdominis basi, coxis femoribusque rufo- 
testaceis ; antennis elongatis, pectinatis ; alis fumatis, venis fuscis. 
Male. Length 3 lines. Black; the head, thorax, and ex- 
treme base of the abdomen rufo-testaceous; the head with a 
deep depression on each side; the antennze emanating from a 
short basal footstalk, one-third longer than the body, and pecti- 
nate; the teeth or branches elongate and pilose. The wings of 
a smoky brown, iridescent, with the nervures dark brown. The 
legs longer than the body; the coxz, trochanters, anterior and 
intermediate femora, the base of the posterior pair, and the 
anterior and intermediate tibiz inside, rufo-testaceous; the 
posterior tibize and tarsi with short black pubescence. 
This beautiful insect, for which I am obliged to establish a 
new genus, has been received from Mr. Wallace, who captured 
it in Celebes; the neuration of the wings, and general habit of 
the species, appear to indicate clearly its affinity to the genera 
Cladius, Trichiocampus, and Nematus, from all of which it is 
separated by having four submarginal cells, and antenne com- 
posed of sixteen joints. The normal number in the Tenthredinidee 
is nine joints; but there are several genera which depart from 
that number : thus, in Sirezx there are twenty-five, in Xiphydria 
thirteen, whilst in Lyda the number varies, in the different 
species, from twenty-one to thirty-four. 
XXXIII.—Descriptions of Freshwater Shells collected in Southern 
India by Lieut. Charles Annesley Benson, 45th M.N.I. By 
W. H. Benson, Esq. 
Tue following shells were discovered at Quilon, on the Malabar 
coast, in the territory of Travancore, a portion of country which 
_ appears hitherto to have escaped the researches of conchologists. 
Among other species, the little-known Melania Riquetii, De Grate- 
loup (figured and described by that author in the ‘ Acts’ of the 
Nat. Hist. Society of Bordeaux), from Bombay, was found to 
accord perfectly with the published type, which appears to have 
been subsequently described by Lea under the designation of 
M. Tornatella. The figure in the ‘Iconica’ (173 d) delineates 
the sculpture of M. Riquetii, while that given at 173 a agrees 
better with Souleyet’s M. sculpta, a species which was found by 
the late Dr. Bacon at Singapore. I have seen one of the nu- 
merous varieties of Melania lirata, B. (J. A. S. 1836, sub- 
