100 TROCHUS FILIFERUS. 



lower swollen part of the whorls has compressed folds or 

 tubercles, about 19 on the last whorl; moreover impressed 

 lines, in the direction of the lines of growth, but rather 

 remote and much more conspicuous, are visible with a 

 lens on the last 5 whorls. Base with 12 lirae , much 

 narrower than their interstices and with a tendency to be 

 beaded, especially the distal ones, the interstices con- 

 spicuously radiately striated. Aperture subtrigonal, outer 

 lip thin , curved , interior with about 1 1 lirae at some 

 distance from the margin ; basal margin slightly curved, 

 bidentate, parietal wall slightly callous, with 2 strong and 

 a few indistinct lirae; columella thick, oblique, with a five- 

 dentate margin and an angle at the union with the basal 

 lip; umbilical tract heavy, narrow, funnel-shaped, deep, lirate, 

 white with a pearly lustre, like the interior of the aperture. 



Alt. 29, diam. maj. 25 mm.; apert. alt. 6, lat, 11 mm. 



Blab. Indian Ocean, without exact locality (Boie). 



I cannot identify this shell, which belongs to the col- 

 lection of the Leyden Museum, with any described species ; 

 in general outline it resembles the variety verrucosus Gmel. 

 of T. maculatus Lin., but it is quite different from any 

 known form of this species by its peculiar sculpture; the 

 umbilical tract is much smaller and relatively deeper, etc. 



2. The adult state of Bathybembix aeola Watson. 



In Part XLII of the Zoology of the Voyage of H. M. S. 

 Challenger, Watson has described on page 95 and figured 

 on Plate VII, fig. 13, a shell, under the name of Bembix 

 aeola, previously described by the same author in the 

 » Preliminary Report" (Journ. Linn. Soc. Lond. Vol. XIV, 

 p. 603). Now H. Crosse (Journal de Conchyliologie, 1892, 

 p. 288) has shown in a paper: »sur le genre Bathybembix" ', 

 that the name Bembix has been used by de Koninck for a 

 fossil shell, and changes therefore the name in Bathybembix. 

 Mr. Crosse suggests that Watson's specimen is not adult, 

 and that it should belong in one genus with Trochus 



Notes from the Leyden Museum, Vol. XXV. 



