Dr. E. von Martens on some Species of Assiminea. 203 
mann. Whether Assiminea is rightly supposed to be an air- 
breathing (pulmonate) mollusk I am not prepared to decide ; the 
Teenioglossan conformation of its radula is affirmed by Troschel, 
i. c. pl. 7. figs. 138 & 14. 
All the species of Assiminea which I have observed alive dwelt 
in brackish water, on the muddy banks of rivers, channels, or in- 
lets very near to the sea, never in fresh water, never on the open 
sea-shore, neither on rocks and stones, nor on plants, but simply 
on the muddy flat itself, near high-water mark, during the ebb, 
surrounded by the air; but I cannot affirm that in every case they 
were covered at flood-time by the water. I have found them in 
such situations in China, Siam, and Singapore; and the same I 
suppose, after consulting various English authors, to be the case 
with the British species A. Grayana. 
The species I have observed are the following: — 
1. Assiminea carinata, Lea, Proc. Acad. N. Se. Philadelphia, 
1856, p. 111. 
Omphalotropis maculata, m., Proc. Zool. Soc. 1860, p. 11. 
Siam, on the muddy banks of the channels of the Menam 
river, below Bangkok. 
Resembles in size and outline the Bengal A. Francisct, but is 
distinguished by a sharp keel round the umbilicus and by some 
rows of dark spots and a dark basal band. I was myself mis- 
taken, before starting with the Prussian Expedition for Eastern 
Asia, in describing a specimen of this shell, collected by the 
late M. Mouhot and examined in the British Museum, as an 
Omphalotropis. During my stay m Siam I found it alive, and 
recognized the true characters of the mollusk ; this I stated, in 
the ‘Malakozoologische Blatter, edited by Dr. Pfeiffer, vol. x. 
(1863) p. 120; nevertheless the editor himself, in his ‘Second 
Supplement to the Monograph of Pneumonopoma,’ 1865, p. 176, 
enumerates it among the Cyclostomacea, and near it the Hydro- 
cena fasciolata, Crosse & Fischer, and H. fulvida, Pfr. (Journ. 
Cench. vi. & x.), which are evidently later names for the same 
species. 
2. Assiminea pinguis, m. 
A. testa globoso-ovata, vix rimata, oleoso nitente, linea impressa infra 
suturam notata, fusco-aurantiaca, unicolore ; spira conica, acutius- 
cula; anfr. 5, paulum convexi, ultimus infra rotundatus, carina 
nulla; apertura spiram eequans, fere verticalis, supra acute angulata ; 
peristoma rectum, margine externo tenui, columellari incrassato. 
Long. 6, diam. 4, apert. alt. 3, lat. 2 millim. 
Makao, in a muddy inlet. 
Head of the animal grey ; foot below yellow, with bluish edge. 
