PACE: ON BUCCINUM DERMESTOIDEUM, LAMK. 257 
tentacles, such as are met with in most species of Nassidex, are 
seemingly present, though I was not able to make them out quite 
satisfactorily. 
Radula.—The characters of the radula (Figs. 7-11) at once separate 
Pseudamycla from the Columbellidee ; and, while the radula is some- 
what similar in type to that met with in Prsania, Tritonidea, Cominella, 
etc., nothing quite like it is known to me as being represented in any 
Buccinoid genus. Prof. H. M. Gwatkin also, who has kindly examined 
a specimen for me, can find nothing comparable with it among his 
extensive collection of radule. The radule of seven individuals 
were examined, and in each the structure was substantially the 
same. It consists of about 100 rows of the formula 1-1-1. The 
tridentate central tooth is remarkable for its comparatively small size, 
and for being much longer than it is broad. The laterals, having their 
bases much prolonged backwards, are roughly triangular in outline: 
they are armed normally with four cusps, but a minute denticle is 
occasionally present at the base of one or other of the cusps. The teeth 
appear to articulate with each other in the manner indicated in the 
figures, which were drawn after examining a large number of isolated 
teeth mounted in various positions in different media and under 
varying conditions of illumination, and they represent what I believe 
to be the true form of the teeth; but the correct interpretation of the 
structural details of a radula is always difficult, and, no matter how 
much time be expended upon the investigation, the result is never 
entirely satisfactory. 
Regarding the systematic position of Psewdamycla. The supposed 
possession of caudal tentacule would strongly suggest affinity with 
Nassa and Bullia, and the shell is also not so very dissimilar, but the 
characters of the radula absolutely preclude any closer association 
with these groups than with the Columbellide. The radula of 
Donovania minima (Mont.) as figured! by the late Martin Woodward 
presents considerable similarity to that of Pseudamycla, but the details 
recorded are insufficient to enable me to judge if this resemblance 
is more than a merely superficial one. Anyhow, pending further 
investigation of the soft parts, Psewdamycla may best be placed among 
the Pisaniine. 
As to whether any other supposed species of Columbellide will have 
to be transferred to Pseudamycla, only further anatomical research 
will decide, but I think it at least highly probable that Columbella 
miltostoma, Ten.-Wds., from Tasmania, will prove to be closely related 
to P. dermestoidea, and may even be conspecific with it. 
1 Proc. Malac. Soc. Lond., vol. iii, p. 238. 
