198 PROCEEDINGS OF THE MALACOLOGICAL SOCIETY. 



oblique groove behind the outer lip. Aperture vertical, somewhat 

 triangular, with three lamellae on the parietal wall, three on the 

 baso-columellar margin, and a large obliquely-entering plate-like fold 

 within the outer lip, its upper end being bifid. Peristome broadly 

 expanded, white. Body-whorl whitish, with three broad blackish- 

 brown uninterrupted bands, the upper one broadest. The upper 

 whorls are dark brown, with a white subsutural band. Alt. 1 1'5 mm. ; 

 greater diara. 15'5, lesser diam. 10 mm. 



Collected by Mr. Francisco Dias da Rocha, to whom the species is 

 dedicated. 



The four specimens examined are quite similar, but in two of them 

 the dark colour of the last whorl is divided in four bands, and another 

 example is very pale, the bands nearly completely disappearing, 

 except on the base, where the umbilical rimation is bordered with 

 dark brown, as in the other examples. The aperture, in all specimens, 

 is white on the lip and darkish around the folds. 



This species is allied to T. clausus, but is larger, with a more 

 elevated spire, and a much broader aperture. The uppermost parietal 

 fold is united above to the peristome m T. clausus, whereas in T. Rochai 

 it is a little remote. 



ToMiGERUs coRKUGATus, n.sp. Fig. 3. 



This species is closely allied to T. Rochai, but larger and with 

 a shorter spire. The bands are the same, but in one of the two 

 examples they appear only at the base. As the differences in the spire 

 coincide with those of the dimensions, I have no doubt that the two 

 species are really different. Alt. 13mui. ; greater diam. 21, lesser 

 diam. 12 mm. 



TOMIGERTJS CLATJSITS, Spix. 



Tomigerus claiism, Pilsbry : Manual of Conchology, ser. ii, vol. xiv, 

 p. 106, pi. vii, figs. 67-70. 



The examples collected by Mr. Dias da Rocha correspond with the 

 description given by different authors. The coloration varies from 

 white to pale-brownish, the dark bands always being well developed. 

 The largest specimen has the following dimensions: alt. H'omm. ; 

 greater diam. 17, lesser diam. 11 mm. 



T. clausus seems to be the most common species of Tomigerus in 

 Ceara. 



The species described above are of interest in various respects. 

 A new type is represented by T. IcBvis, remarkable for its smooth, 

 very white, and somewhat transparent shell, but the brown band of 

 the umbilical suture shows that this species is related to the banded 

 forms. It is a rule in the species of Tomigerus, if the bands are 

 disappearing, that they are retained longest on the under side and 

 principally along the umbilical suture. • Likewise the two other 

 species, which are closely allied, exhibit a feature not yet found in the 

 genus. On them the anastomosing branched riblets or wrinkles, 

 which only feebly exist in T clausus, are very strongly developed. 



