416 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
INVERTEBRATA. 
Mollusca. 
a. Cephalopoda. 
Notes on Structure of Sepia.* * * § — Mr. R. H. Burne finds in tliemale 
a funnel which seems to be the remains of a former channel of communi- 
cation between, the body-cavity and the peritoneal sac surrounding the 
genital duct, thus supplying an additional argument in favour of the 
coelomic origin of the sac. 
He also describes a series of slender rods of cartilage (one to each 
gill lamella), standing out from the branchial gland and stiffening the 
free edge of each supporting membrane. 
y. Gastropoda. 
Reno-Pericardiac Pore in Ampullaria TJrceus.f— Mr. E. H. Burne 
has been able to find, what von Erlanger suspected, and what Bouvier 
failed to detect, a pore from the pericardium into the left kidney. “ The 
present features of the pore are sufficiently peculiar to warn one to be 
cautious in assigning great weight to it in any attempt to determine 
which kidney of Ampullaria is the representative of the single kidney 
of the monotocards.” 
Variations and Mutations of Littorina.J; — Mr. H. C. Bumpus 
makes a third contribution to the study of variation, namely an account 
of the variations and mutations of the periwinkle, Littorina littorea , in- 
troduced on the North American shores. He examined 3000 British 
shells and 10,000 American shells, 1000 shells being considered sufficient 
to represent any given locality. He concludes, from his measurements, 
&c. that the periwinkle, subjected to a new environment, and presumably 
emancipated from many of the restraining influences of natural selection, 
has become in any and in all of the American localities, more variable 
in stature, course of growth, weight, and bulk, as also in the limitations 
and boundaries of the colour patterns. While presenting extremes of 
variation, the American type, compared with the European type, is 
more elongated, lighter in weight, more bulky, and with less pronounced 
colour-markings. These results are in harmony with and fully corro- 
borative of the conclusions reached from the statistical study of the 
sparrow’s cgg.§ 
Gastropods of the Great African Lakes. || — Mr. J. E. S. Moore dis- 
cusses the various theories as to the origin of the Halolimnic animals 
of the Great African Lakes. The only way of reaching a satisfactory 
conclusion is through a minute knowledge of the morphology of the 
individual members of the Halolimnic group, and of these the Gastro- 
pods are most suitable. If it can be shown from the study of their 
structure that the Halolimnic Gastropods in Tanganyika are most closely 
related to the freshwater Gastropods at present known, then the theory 
of the ancient freshwater origin of the Halolimnic group is probably 
* Proo. Malacol. Soc., iii. (1898) pp. 53 6 (2 figs.). 
f Tom. cit., pp. 49-52 (1 fig.). 
X Zool. Bulletin, i. (1898) No. 5, pp. 247-59 (14 charts and 2 figs.). 
§ Cf. supra , p. 410. |] Quart. Journ. Micr. Sci., xli. (1898) pp. 159-80. 
