566 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
great intensity, though some of the organs have escaped. The eyes and 
antenum have especially felt the influence of the surrounding medium ; 
the influence on the carapace has been less definite and is less easy to 
explain, and much the same is true of the abdomen. The oral appendages 
seem to have been affected more by a general law of evolution than by 
adaptation to external influences. The branchial formula of the family 
is of the same type as that of the Astacidae. 
With regard to coloration the Galatheidas may be divided into those 
that can and those that cannot receive visual impressions ; in the latter 
colour may entirely disappear. 
The ova vary greatly in size ; when numerous they are rarely more 
than half a millimetre in diameter ; the ova of the blind species are 
ordinarily larger, and those of Diptychus and Ptychog aster are often 
2 mm. in diameter. The development of the former of the two just- 
named genera has been followed out, and seen to closely resemble that 
of the Crayfish, as described by Reichenbach. 
After discussing the details of the sub-groups and of the genera a 
table is given to show the chief characters. 
The geographical and bathymetric distribution is next considered ; 
as to the latter, it is pointed out that there is not in the whole of the 
Animal Kingdom, a family which presents more variety than this. It 
has representatives at all depths, and in fresh water they are represented 
by a single species. The authors come to the conclusion that the deep- 
sea Galatheinae are exclusively represented by an important section of 
the species which are furthest removed from the macrurous type (blind 
Galatheinae) ; in proportion as the littoral is approached these species 
yield to o'thers which are less removed from the primitive forms, and, in 
the sublittoral zone, they are replaced by others which are still nearer ; 
in this same there is met Avith the other section of the species furthest 
removed from the Macrura (Porcellaninae), and these species predominate 
and become more and more numerous as the littoral is approached. 
These conclusions are, of course, the exact opposite to those to which 
the same authors were led by a study of the Paguridae, whether they 
learnt that the Pagurid fauna of the deep is chiefly constituted by species 
more or less near the macrurous forms, and that these species disappear 
as the littoral is approached, Avhere they yield to others which are further 
removed from the primitive types. As the authors well remark, these 
very divergent conclusions show with what prudence we must try to 
generalize about abyssal animals. 
The authors conclude a very interesting essay with some observa- 
tions on the geographical distribution of the family. 
Lomisinae.* — M. E. L. Bouvier forms this new group of Anomurous 
Crustacea for the genus Lomis, which has not, he thinks, any direct 
affinities Avith the Litliodinae, but forms an independent subfamily of the 
Paguridae. The structural resemblances to Mixtopagurus and Paguristes 
are pointed out, while the differences from the Pagurinae are likewise 
insisted on. 
It is believed that the Lithodinae are derived from Eupagurus , that is 
to say from Crustacea in Avhich a long adaptation to pagurid life has 
made the abdomen very unsymmetrical, reduced to a vestige the dorsal 
* Comptes Rendus, cxviii. (1894) pp. 1353-5. 
