194 SUMMARY OF CURRENT RESEARCHES RELATING TO 



In the lobster, a walking-leg must be held in order that autotomy may 

 be effected. This points to the probability that, in the lobster and its 

 allies, evasion of an enemy has been the most important factor in the 

 production of autotomy. Among crabs an-est of hoemon-hage must be 

 regarded as the chief result of autotomy. A new description of the 

 mechanism and nature of autotomy in the Macrura and Brachyura is 

 given. 



Fresh-water Crabs of Ceylon.* — Jean Roux has made a revision of 

 the fresh-water crabs of Ceylon, which, like those of peninsular India, 

 all belong to the genus Pamtelphusa. Six species are recognized, and 

 Barytelphusa, Oziofelphusa, and Liotelphusa as sub-genera. 



Sub-antarctic Isopods-f— Charles Chilton discusses the genus Deto 

 and six species. One of the most striking features is the great sexual 

 dimorphism exhibited apparently by all the species, and the varied 

 forms that this takes. Thus in D. hucculenta, the male differs from the 

 female in the possession of extraordinary balloon-like expansions of the 

 first segment of the peraeon ; in iJ. auc/dandicc, in the longer spines 

 arising from the segments of the person ; and so on. All the species 

 live on the sea-shore and are branchial breathers. The nearest affinities 

 of the genus are probably with Scyphax and Scyphoniscus. As regards 

 geographical distribution, they add a good example to the cases already 

 known of closely allied forms being found on widely separated shores 

 in sub-antarctic regions. 



--te' 



Stomatopod Crustacea from Philippines. |— Stanley Kemp reports 

 on a collection of Philippine Stomatopoda, which includes some 

 interesting species, such as Lysioxquilla vicina Nobili, which, like its 

 near relative in California, seems to inhabit burrows made by Balano- 

 glossus, and L. mvltifasciata Wood-Mason, represented by nine 

 specimens which illustrate the manner in which the characteristic pig- 

 mentation is developed. The author describes Gonodactyhis proximus 

 sp. n., and contributes a useful discussion of allied species. 



Genus Lern8eodiscus.§ — Oeoffrey W. Smith has studied what he 

 previously called Triatu/iflus munidae, and finds that it should be ranked 

 in the genus Lernseodiscus F. Miiller. The genus Triangulus is with- 

 drawn, and Kollmann's correction of the author's previous interpreta- 

 tion of the orientation of the parasite is accepted. The genus Lernseo- 

 discus is thus defined: — External body of the adult yellow. Roots 

 yellow, widely distributed and ramifying, without lagens. Mantle 

 highly muscular, and thrown into lappets or folds to a greater or less 

 extent. Mantle-opening situated either in the middle line, or more 

 usually deflected to the right side, relatively to the host. Mesentery 

 broad, pierced by the peduncle, which separates two hinges ; the mor- 

 phologically right hinge being applied to the thoracic surface, the left 



* Rev. Suisse Zool. xxiii. (1915) pp. 361-84 (2 figs.). 



t Journ. Linn. Soc. (Zool.) xxxii. (1915) pp. 435-56 (2 pis.). 



t Philippine Journ. Sci., x. (1915) pp. 169-87 (1 pi.). 



§ Journ. Linn. Soc. (Zool.) xxxii. (1915) pp. 429-34 (1 pi.). 



