324 SUMMARY OF CURRENT RESEARCHES RELATING TO 



during the Prince of Monaco's expeditions show that this form is abun- 

 dant in the Azores. The last-named collections contain this species- 

 only ; and as both sexes occur, the author has been enabled to draw up a 

 detailed comparison between the male of Sperchon glandulosus and that 

 of S. brevirostris. 



e. Crustacea. 



Notable Crustacea.* — Dr. A. Alcock describes a new hermit-crab 

 (Chlsenopagurus g. n.), noteworthy (1) in Laving for its refuge, not the 

 usual mollusc shell, but a sheet or blanket formed by the ccenosarc of 

 a colony of sea-anemones ; (2) in being — as far as the male is concerned — 

 symmetrical ; and (3) in having the appendages of the third and fifth 

 somites of the male and of the second and fifth segments of the female 

 present on the right or left side indifferently. The sea-anemone, belong- 

 ing to the Zoanthida3, merely forms a sheet, which the crab simply tucks 

 under its telson by one end and pulls over its back by the other end — 

 the polyps seeming to have no power of adhesion and to depend on the 

 crab for a fast hold. The peculiar interest of the case is that the two 

 animals seem to have become directly adapted to one another, and to be 

 incapable of a separate and independent existence. 



Alcock also describes Domecia glabra sp. n., distinguishing it from 

 its sole congener D. hispida, and makes notes on Latreillia pennifera 

 sp. n., and Latreillopsis bispinosa. 



North American Cancroid Crabs. j — M. J. Eathbun gives a synopsis 

 of the tribe of Cyclometopous or cancroid crabs (including Cancridae, 

 Pilumnidfe ( = Xanthidee), and Portunidse, with a key to the genera and 

 species. 



Alleged Rudimentary Eyes of Niphargus.| — Prof. F. Vejdovsky 

 finds that in none of the species of Niphargus which he has investigated 

 is there any organ corresponding to a normal Arthropod eye. Only in 

 Niphargus puteanus can there be any suggestion of an eye-rudiment, and 

 even here the degeneration has gone so far that the optic part of the 

 primordium is quite subordinate, and the whole becomes a sinew-like 

 structure bracing the large cerebral ganglion to the wall of the body. 



Larva of Epischura lacustris.§ — Prof. C. Dwight Marsh has some 

 notes on the structure of the larva of this Copepod, which is found only 

 in America (its nearest European relative being Heterocope), and is re- 

 markable for the very pronounced asymmetry of the abdomen. In the 

 male of Epischura lacustris Forbes, not only is the abdomen twisted to 

 the right, but certain of the segments have marked lateral projections 

 which together form a complicated grasping organ. The author deals 

 especially with the male abdomen and the male fifth feet. The fact 

 that the asymmetry of the abdomen and the lateral processes of the seg- 

 ments appear only in the very last stages, points strongly to the pro- 

 bability that this most marked peculiarity is a recent development, and 

 that Epischura may be quite closely connected with forms having sym- 

 metrical abdomens. 



* Journ. Asiatic Soc. Bengal, lxviii. (1899) pp. 111-9 (1 pi.). 



t Amer. Nat., xxxiv. (1900) pp. 131-4H (5 figs.). 



J SB. k. bohmisch. Ges. Wise., 1900, 12 pp. (1 pi.). 



§ Trans. Wisconsin Acad., xii. (1900) pp. 544-9 (2 pis.). 



