15 



Species. 



309 



318 



25 



477 



As far as the marine species are concerned, the district cannot be said to possess 

 any interest of its own, since it is only a part of the great region which extends 

 from E. Africa and the Red Sea to the Sandwich Islands and tropical Australia, 

 and includes all the countries washed by the Indian and W. Pacific Oceans. 



The Land Mollusca of this great district (which practically includes the whole 

 of Indo-China minus Burmah and the Malay Peninsula) consists of: 

 Inoperculates 18 genera = 206 species. 



Operculates 17 ,, = 103 ,, 



the proportion of operculates being very high, as much as one-third of all the land 

 mollusca. 



The inoperculates consist of Streptaxis (18 sp.), Ennea (1), Helicarion (7), 

 Ariophanta including Microcystis, Macrochlamys, Kaliella, Hcmiplecta, Ryssota (44), 

 Trochomor'pha (o), Geotrochus (2), [query whether Geotrockus proper extends so far 

 west], Helix (50), the principal groups being P/ectopylis, Plectotropis, Trachea, 

 Fruticicola, Acusta, Chloritis (?), Camaena and Hadra ; Amphidromus (34), 

 Bocourtia [a genus of doubtful value, established by Rochebrune for a group of 

 Bitlimiims in shape resembling Limncca paiustris] (2), Hypselostoma (2) [this 

 remarkable genus has lately been detected by von Mollendorff on Cebu, one of the 

 Philippine group], Tonkinia [one of Mabille's genera of doubtful value] (1), 

 Clausilia (14), Opeas (7), Spiraxis (2), Subulina (1), Siiccinea (4) [a remarkably 

 small number for so well-watered a region], Vagimtla (7). 



The operculates consist of Assiminca (7), Procyclotus [= Cyclotus Pfr. et auctt.] 

 (6), Dasytheriitm [a formidable name, suggestive of some shaggy-haired quadruped 

 of pre-historic times rather than a gentle Cyclotus with a prickly epidermis], (2), 

 Opisthoporus (5), Rhiostoma (6), Myxostoma (1), Pterocyclus (7), Cyclophorus (28), 

 Leptopotna (10), Lagoclulus (6), Pitpina (7), Hybocystis (3), Alycaeus (6), Catanhis 

 (1) [the presence of this genus is remarkable, if authenticated, since it is hitherto 

 known only from Ceylon, part of S. India, and the Nicobars], Diplommatina (2), 

 Helicina (4), Georissa (2). 



The Fluviatile Mollusca consist of 28 genera and 318 species, and fall under 

 the following headings. Gasteropoda: 17 genera and 168 species, prominent 

 among which are Melania (39), Paludina (38, a very large proportion), Canidia 

 (13, a genus which finds its metropolis in Indo-China), and the peculiar genera 

 IVattebledia, Pachydrobia, Jnllienia and Lacunopsis. Pelecypoda : II genera 

 and 150 species, among the more noticeable of which are Unto (63), Corbiada 

 (35), Mycetopits, hitherto only known from S. America (1), Dipsas and Arconaia 

 (peculiar to E. Asia). 



In all probability further investigation will at once add to and diminish the 

 molluscan riches of this country, by the discovery of new forms, and also by the 

 gradual weeding out of species which have been hastily described on insufficient 

 evidence. Dr. Fischer has not been able to discuss this latter question, for many 

 of the so-called species of the later French school (to which he is strenuously, and 

 in our opinion, most justly opposed), have never been figured. — A.H.C. 



Manual of Conchology by George W. Tryon, Jr. and H. A. Pilsbry, 



1st Ser. Vol. 13, pt. 3, and 2nd Ser. pts. 25 — 27. Philadelphia: Academy of 



Natural Sciences. 

 The parts to hand of this well-known manual, maintain the high standard and 

 excellence of their predecessors. Part 3 of Series I, deals with the genera 

 Nacella and Helcioniscus , the former being divided into Nacella and Patinella, 

 while the latter is dealt with geographically and divided into six groups, viz., 

 Chilian, Polynesian and East Indian, Japanese and Chinese, New Zealand and 

 Australian, East African, from the Red Sea to the Cape, and those of unknown 

 locality. The synopsis given on p. 79 of this volume, is varied on the ground 

 that Nacella, Patinella, and Helcion have been discovered to possess two lateral 

 teeth on each side, while Patella, Helcion, Patina, &c, have three. The plates — 

 both anatomical and conchological — are a great advance upon some of those in 

 the earlier volumes. 



