490 
W. T. OALMAN. 
minute form liad not been obtained by any other naturalist. 
Some eighteen years ago a re-examination of the solitary 
remaining specimen enabled me, in spite of its poor state of 
preservation, to add some details to Vejdovsky’s account, and 
led me to the conclusion that it was allied to Anaspides 
(Caiman, 1899). The scantiness of information regarding it, 
however, has caused most writers who have had occasion to 
refer to Bathynella in text-books or elsewhere to suspend 
judgment as to its affinities, and the late Geoffrey Smith 
(1909) omitted it altogether from his revision of the Anaspi- 
dacea. The detailed account of its structure now provided 
by Chappuis from the specimens found in Switzerland entirely 
confirms my earlier conclusions as to its systematic affinities, 
and enables us to say that Bathynella is undoubtedly a 
degenerate member of the Syncarida, a group of Crustacea 
which has persisted from Carboniferous times, and of which 
the only other living representatives are found in Australia 
and Tasmania. 
Certain features in the morphology of Bathynella seem 
to me, however, to deserve somewhat more detailed con- 
sideration than they have yet received, and on this account I 
was particularly glad to have an opportunity of studying 
three specimens that M. Chappuis kindly presented to the 
British Museum (Natural History). From the small size of 
the animal and the unusual delicacy of its cuticular covering 
its investigation presents considerable difficulty, but I have 
been able in great part to confirm and in some details to 
amplify Chappuis’ account of its external structure. Since 
his memoir, published in a German periodical, is likely for 
the present to be difficult of access for many zoologists, it 
seemed desirable to make the following account somewhat 
fuller than might otherwise have been necessary. 
II. External Characters of Bathynella. 
Size. — The specimens examined by me measure almost 
exnctly 1 mm. in length of body, and this is also the size 
