ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 41 



7- Arachnida. 



Anatomy of Boophilus annulatus Say.* — W. E. Allen describes the 

 integument and musculature, appendages, alimentary tract, salivary 

 glands, malpigliian tubules, sex organs, etc., as well as several structures 

 of unknown nature. In the alimentary canal there are six distinct 

 regions. There is no special channel for the passage outward of the % 

 salivary fluid during the act of blood sucking, though it may escape 

 around the upper and outer surfaces of the mandibles. It is also possible 

 that the currents may alternate, saliva flowing in intervals of rest from 

 suction. The salivary glands are of the compound alveolar type, rather 

 over 2 mm. in length. In engorged ticks there appear to be on the 

 anterior wall of the body epithelial folds of a glandular nature, but their 

 use or method of discharging their secretion has not been made out. 



Genera of Water-Mites. f^R. H. Wolcott gives a very useful account 

 of the genera of Hydrachnidaj. The paper embodies all information 

 on the subject published since the issue of Piersig's monograph. An 

 attempt is made at grouping the genera in divisions of higher rank, a 

 type-species is fixed for each genus, and a diagnostic key — artificial, but 

 complete — is given for all the known freshwater genera. 



Phytoptids and Witch's Broom of Birch-Trees.| — H. T. Giissow 

 has studied numerous cases of " witch's broom " on English birch-trees, 

 and he never found one which was due to Exoascus titrgidus, or other 

 mycelial infection. They are due to Phytoptus {Eriophyes) rudis, which 

 also causes the bud-galls. He does not seem to believe much in the dis- 

 tinctions between Phytoptus rudis and related " species." Professor 

 Nalepa found Ph. rudis in the terminal buds. Ph. hetulce in the bud- 

 clusters, and Ph. rudis in the witch's broom. The author describes the 

 structure of the mite and some stages in the development. 



New Species of Fossil Limulus from Jurassic of Sweden.§ — R. T. 

 Jackson describes from the Liassic Sandstone at Hor, in Scania, a frag- 

 ment — a sandstone cast of a portion of the right dorsal side of a large 

 cephalothorax — of what he regards as a new species of Limulus (L. 

 nathorsti). He compares it with the other three or four fossil species,, 

 and notes that this is the first occurrence outside of Germany. 



*• Crustacea. 



Annulus Ventralis of Cambarus.|| — E. A. Andrews describes the 

 peculiar annulus ventralis of the females of the crayfish genus Camharus. 

 Of the nine genera of crayfishes Gamharus alone has this peculiarity, 

 which varies from species to species. It is an elevation of connective 

 tissue covered by epidermis, forming an exoskeletal pocket, with an 

 open orifice at one end and a suture along its side. The male fills this 

 pocket with sperms and seals the orifice with secretion from the vas 



* Trans. Amer. Micr. Soc, xxvi. (1905) pp. 245-80 (4 pis.). 



+ Tom. cit., pp. 161-243 (10 pis.). 



X Zeitschr. f. Land, und Forstw., x. (1906) pp. 1-9 (2 pis.). 



§ Arkiv. f. ZooL, Hi. (3906) No. 11, pp. 1-7 (2 figs.). 



II Proc. Boston Soc. Nat. Hist., xxxii. (1906) pp. 427-79 (6 pis.). 



