154 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Patagonian Mite.* — Ivar Tragardh records the very interesting 

 discovery of an Acarid — Nothrus maximus sp. n. — both as a fossil in the 

 so-called Glossotherium-c&ves of Patagonia, and living in "damp places" 

 in the same region. The material was furnished by the Nordenskiold 

 expedition, and the two fossil specimens occurred in coprolites assigned 

 to Glossotherium, and consisting of vegetable debris. Their position 

 makes it hardly possible to doubt their age, and they present the appear- 

 ance of having been swallowed with food, and rejected in an undigested 

 condition. Their identity with the living specimens appears also incon- 

 testable, a fact of great interest in view of tbe great cbanges wbich have 

 occurred in Patagonia since tbe Glossotherium period. 



(. Crustacea. 



Tropical Plankton."!" — I. C. Thompson publishes a report on two 

 collections, chiefly of Copepoda, made on board steamers by means of 

 tow-nets fixed to water-taps, during voyages in the Pacific, Mediter- 

 ranean, Red Sea, &c. The collections are of interest as showing in 

 many cases an extension of range of known species of Copepoda. 



Palaearctic Isopods.J — Prof. Karl W. Verhoeff finds that the form 

 which he previously described as Armadillidium fruxgalii sp. n. has the 

 epimera of the first and second segments of the body split, and he there- 

 fore erects for it a new genus, Echinarmadillidium. He also takes tbe 

 opportunity to further split up the genus Armadillidium, on the basis 

 of the condition of the epimera in segments one and two. 



Swimming Movements of Entomostraca.§ — D. J. Scourfield points 

 out that, of the four genera into which the old genus Daphnia has been 

 divided, the members of two (Daphnia and Ceriodaphnia) always 6wim 

 either vertically or obliquely back uppermost, while in the genera 

 Simocephalus and Scapholeberis the animals swim obliquely back down- 

 wards. This constitutes a useful method of distinction between the 

 two pairs of genera, and is further interesting in view of the great 

 similarity of the genera to one another. By an ingenious method of 

 experimentation, the author has succeeded in showing that in the case 

 of Daphnia and Simocephalus the difference in position is primarily 

 due to differences in the position of the centre of gravity. Further, 

 he finds that in Daphnia the shell-spines are of much importance in regard 

 to the movements of the animal. 



Ostracoda ofSwitzerland.il — Dr. A. Kaufmann, as the second instal- 

 ment of his work on this subject, discusses the Cypridaa and Darwinu- 

 lidaa. The systematic part of the paper is prefaced by a discussion of 

 the anatomy and habits of the Cypridae, which are represented in the 

 Swiss fauna by 43 species. The Darwinulidae are represented by Dar- 

 winula stevensoni. The paper is very fully illustrated. 



Daphnia hyalina.t — D. J. Scourfield describes this species and 

 figures it beautifully. It appears to be very plastic, for not only does 



* Zool. Anzeig., xxiv. (1901) pp. 25-30. 



t Trans. Liverpool Biol. Soc., xiv. (1900) pp. 262-94 (1 pi.). 



X Zool. Anzeig., xxiv. (1901) pp. 33-41. 



§ Journ. Quek. Micr. Club, 1900, pp. 395-404 (7 figs.). 



|| Rev. Suisse Zool., viii. (1900) pp. 209-423 (17 pis.). 



If Illus. Annual Microsc. for 1900, pp. 9-12 (1 pi.). 



