1865.]| MR. F. MOORE ON BENGALESE LEPIDOPTERA, 755 
THYELLA PULCHRA, H. Adams. 
T. testa subequilaterali, antice longiore, candida, valvarum super- 
ficie costis tenuibus radiantibus et liris excentricis decussata ; um- 
bonibus parvis, subrecurvis ; margine dorsali excavato ; sinu pal- 
liali profundo. 
Long. 13, alt. 11, lat. 7 mill. 
Hab. Singapore (Coll. Cuming.). 
This genus appears to have most affinity with Semele, but differs 
in the absence of lateral teeth, in its more ventricose form, and in 
the position of the internal ligament. The surface of the valves of 
the species described is decussately sculptured by radiating ribs and 
thin concentric lire. 
I avail myself of this opportunity to state that the genus Leu- 
conyx, some time since described by my brother and myself, must be 
cancelled, as we have recently had an opportunity of proving that it 
is founded upon the internal spathulate appendage of Pholas costata. 
The name Plectostoma also, which I gave lately to a very peculiar 
form of Helix from Labuan, must be considered a synonym of 
Opisthostoma, Blanford, which was established to receive a small 
shell from India, much more Pupa-shaped than the type of Plec- 
tostoma, but, I think, belonging to the same group, and which has 
hitherto been supposed to be furnished with an operculum, and to 
be allied to Diplommatina. 
12. On THE LEpIpDoPTEROUS INSECTS OF BENGAL. 
By Freperic Moore. 
(Plates XLI., XLII., XLIII.) 
Excepting a brief list of Lepidopterous Insects from the N.W. 
Himalaya, compiled by Kollar and published in Hiigel’s ‘ Kaschmir,’ 
and another by myself, printed in the ‘ Proceedings’ of this Society 
for the present year, of a collection of Diurnal Lepidoptera recently 
made in nearly the same districts by Capt. A. M. Lang, no record 
has appeared of the many very interesting ‘‘local”’ Indian collections 
that have so frequently been formed. In the following pages a list 
is given of the species contained in a very extensive collection made 
in the Province of Bengal by Mr. A. E. Russell, of the Bengal Civil 
Service, who has kindly placed them in my hands for this purpose, 
and of others collected in the same Province by Mr. W. 8S. Atkinson 
and the late Capt. J. Lind Sherwill. 
Sect. I. RHOPALOCERA. 
Tribe 1. PAprLioneEs. 
Fam. PariLionip&. 
ORNITHOPTERA RHADAMANTHUS, Boisd. Spéc. Gén. Leép. i. p. 
180. 
