ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 175 



able either to last throughout the winter, or to produce resting eggs for 

 the same purpose. Various other points of interest are contained in the 

 memoir. 



Isopods of North-west Coast of North America. * — Harriet 

 Richardson reports on the Isopods collected by the Harriman Expedi- 

 tion. Five new forms are described : Sphcsroma pentodon, Synidotea 

 ritteri, Janiropsis kincaidi, J. calif ornica, and Trkhoniscus paplUicomis. 

 A little-known species, Idotm gracillima (Dana) is figured for the first 

 time, and described more fully than heretofore ; and Asellus tomalensis 

 Harford, is re-described and figured. 



Alaska Decapods.f — Mary J. Rathbun gives an account of the 

 Decapod Crustaceans of the North-west coast of North America collected 

 by the Harriman Expedition. The predominant types are Pandalid, 

 Hippolytid, and Crangonid shrimps, Paguridaa, Maiidse, and Lithodidae. 

 Arctic species often continue southwards through Bering Strait along the 

 west coast of Bering Sea to Okhotsk Sea and the Kurile Islands. Some 

 reach Puget Sound. The winter line of floating ice in Bering Sea 

 determines the northern limit of many species. While many species 

 range continuously from this line southwards to California, others indi- 

 cate a division of that stretch of coast line into several faunas. A few 

 Japanese species were found. The total number of forms dealt with in 

 this report is enormous. One new species, a fietc&us, is notable as the 

 first Alpheid reported from as high a latitude as Sitka. A remarkable 

 case of dimorphism is described in Processa canaliculata Leach ( = Nika 

 edidis Risso). 



Occurrence of Apus in Baluchistan. J — E. Vredenburg gives a 

 brief but interesting note regarding the presence of the genus Apus 

 (species undetermined) in very large numbers in what appeared to be a 

 transitory pool of small dimensions at Thalonk. This is the first record 

 for the genus within the limits of the Indian Empire. 



Annulata. 



Natural History of Tomopteridae.§ — M. Schwartz discusses the 

 structure of the known species of Tomopteris in relation to their pre- 

 dominant habits. He divides the group into those with tail appendage, 

 and those without. Of the former there are two groups, viz. those 

 having a long appendage clearly delimited from the rest of the body, 

 and those having a shorter tail on which are rudimentary parapodia of 

 unequal significance. The long-tailed forms are of floating habit, the 

 others swim actively. Swimming is effected by the beating of the 

 parapodia, the right and left of each pair acting alternately, not 

 simultaneously. The result is a wave-like motion along the body. 

 Steering and balancing are effected by means of the cirri. Tomopte- 

 ridas are probably detritus and vegetable feeders. They are kept alive 

 with difficulty in tanks. 



* Harriman Alaska Expedition, x. (1904) pp. 213-30 (11 figs.), 

 t Tom. cit., pp. 1-190 (10 pis. and 95 figs.). 

 X Journ. and Proc. Asiatic Soc. of Bengal (1905) i. pp. 33-4. 

 § Jena Zeitschr., xxxiii. (1905) pp. 497-536 (1 pi. and 9 figs.). 



