164 PROCEEDINGS OF THE MALACOLOGICAL SOCIETY. 
particularly adapted for a wide distribution ; being attached by a byssus 
to wood and other floating bodies, they would naturally be earried in 
all directions by ocean currents. 
4, Denrattum kpras, Watson.—Dredged by the ‘‘ Challenger’ in 
the North Pacific off Japan in 2,050 fathoms and in the South Pacific 
in 2,160 fathoms, but since recorded from the Gulf of Mexico in 
1,568 fathoms. Both Dr. Watson and Dr. Dall agree in the identi- 
fication of the tropical specimens with this species. Under these 
circumstances it must be removed from the list of species supposed to 
occur only in extra-tropical regions. 
5. Homatogyra atomus (Philippi). — British, Norwegian, Medi- 
terranean, Madeiran, and from the Southern Ocean between Marion 
Island and Prince Edward Islandin 140 fathoms. The identification of 
this species from the last-named locality rests upon the examination of 
‘‘asingle, shghtly weathered specimen ”’ dredged by the ‘‘Challenger.”’ 
I have seen this atom, and although it certainly has very much the 
aspect of this species, and one cannot with certainty say that it is 
different, still, considering the condition of the specimen and its 
minuteness, one cannot equally declare that, beyond a doubt, it is 
conspecific. I can well imagine it to be merely the embryonic shell 
of some Gastrepod which eventually attains much larger dimensions. 
6. Tanruimya rorunpata, Leach. —In respect of distribution this 
species is scarcely worth consideration. Being pelagic throughout its 
existence, one would not be surprised to meet with it both north and 
south of the trepics. The same or allied forms have been met with 
everyWhere in warm latitudes. 
7. Narica (Lunatra) Grorntanpica, Beck.—One specimen considered 
by Watson to belong to this well-known Arctic form was recorded 
by him from Heard Island in 75 fathoms. This is another instance 
in which one feels doubt about pronouncing with absolute certainty 
the correctness of the identification. Although very similar indeed 
to some examples of VV. Groenlandieca, still it differs from most of them 
in being imperforate. In this respect it agrees with WV. fartilis of 
Watson, which was dredged at a neighbouring station in the Kerguelen 
region. Another feature common to both is the presence of a pale zone 
below the suture in the body-whorl. On comparing these specimens 
[ cannot understand why Dr. Watson should have separated the 
Heard Island specimen from the rest. J. fartilis, being devoid of 
colour-markings, has much the aspect of both WV. Groenlandica and 
NV. affinis, also a northern form. 
8. Oposromra RissorpEs, Hanley.—This well-known British species 
is quoted by Watson from between Marion Island and Prince Edward 
Island in 50-140 fathoms. The identification was based upon two 
specimens only, and Dr. Watson distinctly says, ‘‘I give this species 
on the authority of Dr. Gwyn Jeffreys.” After a careful examination 
of the two shells in question I cannot agree with this determination. 
In the first place they exhibit only a faint trace of a columellar tooth 
