418 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Deep-sea Isopods.* — E. L. Bouvier has examined Bathynomus gigan- 

 teus and B. doderleini, the two known species of this remarkable genus 

 of gigantic abyssal Isopods. He finds that the tufts (liouppes) de- 

 scribed by Milne-Edwards as accessory breathing-organs, are placed on 

 the endojwdites of the pleopods, and are larger and more elaborate in 

 B. giganteus than in the smaller species. Their appearance entirely 

 confirms Milne-Edwards' view of their function. The eyes in both 

 cases show adaptation to the abyssal life. Their ocelli in B. giganteus 

 number 3000 in place of the usual 30-40, and are almost double the 

 usual size. Owing to the large size of the animals, it is possible to 

 make out that the sympodite of the pleopods consists of three joints, 

 as does also the peduncle of the antennules. The antennules display 

 a rudiment of an accessory flagellum, a primitive character suggesting 

 affinity with the Anisopoda. The discovery of three segments in the 

 basal piece of pleopods and antennules confirms Hansen's views as to 

 the structure of the Crustacean appendage. The proximal segment of 

 the three, which Hansen believes to be always represented in Crustacea, 

 may fuse with the side of the body, where in Decapods it carries the 

 pleurobranch. In other cases this proximal segment atrophies. 



Ephippium of Bosmina-t — D. J. Scourfield finds that the winter 

 or resting egg in this genus is surrounded by an investment, analogous 

 to the ephippium of the Daphnidse, and formed of a portion of the 

 carapace of the mother. It consists of the valves of the shell, less a 

 considerable portion of their ventral margins, which here, as in many 

 Cladocera, break away at a line of weakness when the ephippium is 

 formed. The use of this is, no doubt, that if the very convex ventral 

 region remained, the shell could not form a closed protective investment. 

 A special peculiarity of the ephippium of Bosmina is the occurrence of 

 3 (1 median and 2 lateral) bands of thickened chitin on its surface. 

 These possibly help to keep the valves firmly closed. 



Giant Ostracods.} — Eev. T. R. R. Stebbing refers to previous de- 

 scriptions of large Ostracoda, and reports the discovery of Crossophorus 

 africanus sp. n., dredged by Dr. Gilchrist in 90-100 fathoms off Cape 

 St. Blaize. " The specimen has a length of 15*5 mm., with a height of 

 12*5 mm., so that the noble Crossophorus imperator and the truly 

 gigantic Megalocypris princeps are positively dwarfed by the comparison." 

 A parasitic isopod (Cyproniscus crossopliori sp. n.) was found inside the 

 Ostracods. 



Marine Crustacea of German Lakes. § — Dr. Max Samter has con- 

 tinued his investigation of the distribution of Mysis relicta and Pal- 

 hisiella quadrispinosa in the lakes of Germany. He has found the 

 former in the Dratzig-See, the latter in the Dratzig, and in the follow- 

 ing, from which Mysis is absent : — the Enzig-See, the large Lubbe-See, 

 and the Pielburger-See. Both are absent from the shallow Vilm-See. 

 In no case was Pontoporeia affinis, which occurs in the Madii, found to 

 be present, but the negative result may be due only to the technical 



* Comptes Rendus, exxxii. (1901) pp. 643-5. 



t Joum. Quek. Micr. Club, 1901, pp. 51-6 (1 pi.). 



X Knowledge, xxiv. (1901) p. 100. 



§ Zool. Anzeig., xxiv. (1901) pp. 242-5. Cf. this Journal, ante, p. 155. 



