312 SUMMARY OV CURRENT RESEARCHES RELATING TO 



which simply lives among the spines of a sea-urchin, whereas this new 

 form is imbedded in the anal region in a capacious invaginated pocket. 

 Only the female was found ; the male is probably free-living. In spite 

 of its close commensalism, almost like endo-parasitism, the crab has a 

 hard, well-calcified shell. It has a dull violet colour, less pronounced 

 than that of the sea-urchin. 



Variations in Number and Arrangement of Male Genital Apertures 

 in Nephrops norvegicus.* — D. C. Mcintosh finds that the male genital 

 openings may occur singly on the right or the left second walking leg, 

 on both the third walking legs, or singly on either the right or the left, 

 or only on the right fourth walking leg, or normally on both sides. 

 F. H. A. Marshall found the percentage of abnormal specimens from 

 the Firth of Forth 12 '2 ; Mcintosh specimens from the Clyde had a 

 percentage of abnormality 2 - 40. 



Proportions of the Sexes in Nephrops norvegicus.t — D. 0. 

 Mcintosh finds that in the Clyde area the proportions of the sexes are 

 approximately equal ; that the size of fully grown males is considerably 

 greater than that of fully grown females ; and that the animals occur 

 together in companies of approximately the same size. 



Scales of Pandalidas4 — H. Coutiere finds that Decapods of the 

 family PandalidEe have a remarkable peculiarity, namely a covering of 

 smooth, transparent, lanceolate scales ("phancres "), each with a short 

 stalk traversed by a central canal. They overlap one another, are 

 readily knocked off, and recall the scales of Lepidoptera. A dozen 

 species were examined, and all exhibited this peculiar cuticular covering. 



Luminosity of Gnathophausia.§ — Gr. Ulig discusses the phos- 

 phorescence of a Gnathophausia, obtained by the German Deep Sea 

 Expedition from a depth of 132G metres. The colour was greenish, 

 and was due to a secretion which exuded from two glands below the 

 cephalothorax anteriorly, at the base of the second maxillre. G. 0. 

 Sars described the structure in Gnathophausia calcarata, and suggested 

 that it was luminous. The secretion is formed in two glandular sacs, 

 which lead into a large reservoir with a duct opening on a papilla at 

 the base of the exopodite. 



Phagocytary Organ of Decapods. || — L. Cuenot has investigated this 

 in a large number of species. There are two distinct lymphoid structures 

 — a globuligenous organ, forming the amcebocytes of the blood, and a 

 phagocytary organ. The former is always situated near the ophthalmic 

 artery ; it completely invests it in some, e.g. Pagurus, it is spread out upon 

 the stomach in others, e.g. Astacns, in others, e.g. Palwmon, it forms a 

 definite mass at the base of the rostrum. The phagocytary organ, except 

 in Nika edulis, is connected with the hepatic arteries. In Decapods with 

 a cephalothoracic liver, the phagocytes envelop the hepatic arterioles ; in 

 the Pagurids, which have an abdominal liver, they cover the numerous 



* Proc. Cambridge Thil. Soc, xii. (1904) pp. 441-4. 



t Loc. cit. X Coraptea Rendus, cxl. (1905) pp. 674-6. 



§ Zool. Anzeig., xxviii. (1905) pp. 662 (2 figs.). 



|| Arch. Zool. Exp., iii. (1905) pp. 1-15 (1 pi.). 



