272 CRETACEOUS GASTROPODA 
e. Sub-family,—POMATIOPSIN 4. 
According to the accounts given by Stimpson of the animal of Pomatiopsis we 
have no hesitation in including in this sub-family the following genera :— 
1. Assiminea, Leach., 1819, (Syn. Optediceros, Leith), (H. and A. Adams, 
Gen., II, p. 314). The shells of the Assiminee are much thinner than those of the 
Lirroriniw#, the teeth of the radula are similar to other Rrssorp~#, but very different 
from those of the former family, and also from those of the Vrrrrarrpz. Gray’s 
statement (Guide, 1857, p. 87,) with reference to the eye-pedicles being united 
with the tentacles in their entire length, is perfectly correct. Our common 
Ass. Francesie can be often seen for days together on dry land, walking or rather 
leaping with great rapidity like a caterpillar of the Gzouzrripx. As the animal 
proceeds, the rostrum and the small foot are moved alternately. There are 
still many doubtful points in the anatomy of <Assiminea. Jeffreys at first says 
(An. Mag., 1859, III, p. 108), that Ass. Grayana and littorea are ‘decidedly 
Pectinibranch’, and in a more recent communication (ibid., 1866, XVIII, p. 309), 
he states, that Assiminea is undoubtedly marine and ‘ pulmonobranch.’ 
Frauenfeld enumerates in his monograph of the genus only five species 
(Verh. Zool. bot. Gesells. Wien, 1863, XIII, p. 210) namely, A. Francesie, 
Gray; A. atomaria, Muhlf.; A. ovata, Krss.; A. fragilis, Quoy; A. sordida, 
Behm. To these have to be added JA. latericea, H. and A. Adams’ (Proc. 
Zool. Soc., Lond., 18638, p. 434); 7A. subrotundata and probably ? Paludinella 
castanea, Carpenter, (Ann. Mag. N. Hist., 1865, XV, p. 28); A. lutea and 
cincta, A. Adams, 1868, (An. Mag. VIII, p. 307) from Japan; A. carinata, 
Lea; A. pinquis, Mart.; A. miniata, Mart.; A. Grayana, Leach; A. Charreyi, 
Morel.; A. helicoides, Gundlach; A. radiata, Pfr.; A glabrata, Pfr.; A. lirata, 
Morel.; A. albescens, Pfr.; A. solidula, Pfr.; A. ventricosa, Homb. and Jacq. ; 
A. rosea, Gould; A. bulimoides, Homb. and Jacq.; 4. dubia and Huaheinensis, 
Pfr. ; A. maritima, Montrouzier; and probably also Realia producta, abbreviata and 
Sragilis, of Pease ; Laguncula pulchella, Benson, and Paludina pulchella, Hutton. 
(Vide Martens in Ann. Mag. Nat. Hist., 1866, XVII, p. 202, etc.); farther 
Ass. rubida and debilis, Gould, Proc. Boston Society, VII, p. 41; As. (Optediceros) 
cornea, (not idem Pfr.), subconica and marginata, Leith, Bombay Roy. As. Soe., V, 
p. 145); A. rubella, Blf. (Journ. As. Soc., Bengal, 1867, pt. I, p. 55, pl. 18, 
figs. 11-12) from the Irawadi Delta, and JA. rotundata, Fairbank, (apud Blanford 
in Ann. Mag. Nat. Hist. for 1868) from the neighbourhood of Bombay. - 
2. Pomatiopsis, 'Tryon, the animals of which mostly live out of water and are 
truly amphibious. The foot is similarly constructed to that of Assimimea, and the 
mode of progression is also similar. 
d. Sub-family,—TRUNCATELLINA. 
Though Stimpson excludes this group of shells from the Rissom#, we hardly 
believe that there is sufficient reason for doing so. The animals do not differ essen- 
tially, and in many respects they very closely resemble those of the previous sub-family. 
