226 Bulletin American Museum of Natural History [Vol. LIII 
denticies, the basal denticles united by a ridge which rises higher than 
they in the middle. Between this ridge and the basal plate there is a 
hollow in which the anterior part of the next tooth fits! The lateral 
tooth has 8 denticles and a body shaped as in Amnicola. The marginals 
have 6 and 12 denticles, those of the inner marginal larger, as usual in 
_Syncera. | 
From the small number of denticles on the central tooth one would 
think this snail related to Syncera, were it not that Benson states that the 
eyes are at the bases of the tentacles. He was well acquainted with 
a | b 
Fig. 25. Tomichia ventricosa (Reeve). Central tooth from above and in profile. 
b, posterior border of basal plate; d, basal denticle; r, ridge connecting basal denticles. The 
profile view is diagrammatic. 
Syncera, mentioning its pedunculate eyes, so that his observation is — 
evidently trustworthy. Under the circumstances, we place Tomichia 
in the Amnicolide, pending further study of the anatomy. If correctly 
referred to this family, it will require a new subfamily, Tomichiine. 
Only one species is known, from South Africa: 
Tomichia ventricosa (Reeve) = Truncatella ventricosa ‘‘Sowerby’’? ReEve, 1842, 
‘Conchol. System..,’ IT, p. 94, Pl. chxxxu1, fig. 2; Pretrrer, 1846, Zeitschr. f. Malakoz., 
III, p. 189; J. Taree, 1921, ‘Deutsch. Stiidpolar Exped. 1901-3,’ XVI, p. [99], fig. 1. 
Truncatella capensis “‘ Krauss’’ Preirrer, 1846, Zeitschr. f. Malakoz., III, p. 189. 
Hydrobia caledonensis CHaPER, 1885, Bull. Soc. Zool. France, X, p. 484, Pl. x1, fig. 6. 
Cape Colony (type locality: Swellendam). 
Tomichia ventricosa var. brevis (Krauss) =Truncatella ventricosa var. brevis 
Krauss, 1848, ‘Stidafrik. Mollusk.,’*p. 87. Cape Flats and Zoetendal Valley, Cape 
Colony. 
Syrnolopside 
The shell is small, imperforate, long and slender, of numerous (7 to 18) whorls, . 
which may be smooth or sculptured spirally or axially. Aperture small, the lip 
rere figures ape notes oe rhe cena tooth ib Bune tied by Dr. H. Burrington Baker. The dia- 
g matic reconstruction of the profile view was made by readings of the scale of th j 
as no tooth was actually seen in this position. e é ee ment, 
