en eee eS 
1923.| Zoological Results of Expedition to Yunnan. 4038 
1 have not seen this species, which is only known from 
Heude’s description and figures. 
Subfamily TricuLixnar 
1924. Triculinae, Annandale, American Journ Hygiene, Monographic 
Ser. III, p. 276. 
have recently proposed this new subfamily for the 
genera T'ricula Benson, Taihua Annand. and Oncomelania 
Gredler. ; 
Genus Tricula Benson. 
_ 7. gregoriana is figured in the paper cited Plate XXXVI. 
Figs. 1, 2. 
Tricula gresgoriana Annandale. 
Shell small, solid, slender, elongate, ovate, conoidal, 
acuminate, naturally pale fulvous but covered with a blackish 
deposit, with strong longitudinal striae, with 64 whorls; the 
Suture impressed, not very oblique, with the upper margin of 
the whorls narrowly flattened outside it: the body-whorl in 
dorsal view about as deep as the two preceding whorls together ; 
the umbilicus imperforate; the mouth ovate, oblique, sharply 
pointed and slightly retroverted above; the peristome thin. 
continuous. 
Operculam horny, thin, paucispiral, ovate. 
Type-specimen. M 128°S, Z.S.1. (Paratypes sent to the 
British Museum.) 
_ Locality. Cliff above the Mekong at the Awa bend, 
Yunnan: altitude 6,400 feet. 
Family DELAVAYIDAE, nov. 
I propose this new family for the peculiar Chinese molluscs 
of the genera Delavaya and Fenouilia Heude, Parapyrgula 
Annandale and Prashad and Paraprososthenia Annandale. 
All these genera are apparently endemic in Yunnan as living 
forms, but Paraprososthenia is also known as a tertiary fossil 
from the Northern Shan States of Burma. 
The family may be defined as follows: 
__ Small pectinibranchiate gastropods of lacustrine habitat 
with thin but porcellaneous shells of turrited or trochiform 
(or neritiform) shape and covered with a thin adherent, but 
at either side; the laterals with a single very . 
prominent cusp, with or without small subsidiary denticula- 
tions; the marginals with a homogeneous series of sharp 
