152 
MOLLUSCA. 
known only from the shell, and described as Vitrina by others, belong very 
probably also to this division. 
b. Species without horny papillae within the penis : — Helicarion frey^ 
cineti and II. ciwieri, F4r., from Australia, and II. pfeiferi, Philippi, from the 
Fiji Islands, with helicoid shells } genital apparatus pi. 3. figs. 6-8 : dentition 
pi. 6. figs. 10, 11, and 14. Semper, 1 . c. pp. 20-31. 
Helicarion soydianus, sp. n., Martens, S13. nat. Fr. 1870, p. 66, Samarkand.. 
Microcystis^ Beck, elevated to the rank of a distinct genus by C. Semper y 
sexual apparatus ver)'^ simple, without appendicular organs j only one caecum 
at the penis. Some species are viviparous. M. myops, Dohrn, succineay 
Pfr., upolensis and perpolitay Mouss., which are anatomically identical, and 
pala'msis, O. Semper, pi. 2. fig. 16, from the Palau (Pelew) Islands: the 
genital apparatus and dentition figured pi. 3. f. 11, pi. 4. fig. 9, and pi. 6. 
figs. 21, 22, and 34. The following are known only from the shell i-^yla~ 
herrima, sp. n., pi. 2. fig. 10, Mariveles, Luzon, 1500-3000 feet above the sea, 
lactea, sp. n., pi. 2. fig. 9, Arayat, Luzon, wilsoni, 0. Semper, pi. 2. fig. 11, 
margaritacea, O. Semper, pi. 2. fig. 16, and stra7nmea, sp. n., p. 48 j the three 
last from the Palau Islands. Semper, /. c. pp. 43-48. 
Nanina nodulata and excrescens, spp. nn., Mousson, J. de Conch, xviii. 
pp. 114, 116, pi. 7. figs. 4, 6, Fiji Islands, referred by the author to the sub- 
genus Microcystis. 
MacroceroSj gen. nov., proposed by C. Semper for Helix speciahilis, Pfr., 
from Samar, Philippine Islands. Genital apparatus simple, without appen- 
dicular organs ; teeth of the radula entire and blunt. The living animal 
figured pi. 1. figs. 6, 7 j sexual apparatus pi. 4. fig. 4 ; jaw and dentition 
pi. 6. fig. 23. Semper, 1. c. p. 49. 
Nanina. Prof. C. Semper breaks up this genus into several 
smaller ones, founded chiefly on the presence or absence of 
some appendicular organs in the sexual apparatus, and of a 
horn-like prominence above the mucus-pore. These generic 
divisions do not agree with the concliological subgcnera of 
former authors j and so the author is forced to use the names 
Xesta, Rhysota, Ailophanta, and Helicarion in a somewhat dif- 
ferent sense than has been done hitherto. The name Nanina is 
purposely omitted. He arranges them, together with the other 
known genera furnished with a mucus-pore forming his family 
Zonitidae, in the following manner : — 
Xesta, Albers, also elevated to tlio rank of a distinct genus by 0. Sem- 
per. Shell-lobes of the mantle varying in extension and development j a 
cylindrical appendicular gland with a cartilaginous terminal papilla, a sac 
with calcareous concretions at the vas deferens, a caecum at the penis. Outer 
lateral teeth of the radula bicuspidate. Shell of very different form, vitri- 
noid or helicoid. 
a. Shell-lobes very large, left cervical lobe not divided j shell vitrinoid. 
X. cumingiy Beck, from Mindanao, lives on trees, like Helicarion ; the living 
animal figured pi. I. fig. 4 ; the sexual apparatus pi. 4. fig. 6, and pi. 5. figs. 
6-10 j dentition pi. 6. fig. 28. The female appendicular gland is very ex- 
actly described, and declared to be the analogue of the multifid gland of the 
