ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 183 



parisons with other species, and discuss the geological bearing of their 

 •discovery. 



Secretion in Female Gonads of Hydrachnids.* - -Karel Thon 

 recalls a communication made by Balbiani, t in 1897, on the secretory 

 •capacity of the epithelium of the female gonads of spiders. In studying 

 E ulais-nym^hs, Thon found that the interior of the gonads was full of 

 large, tough, glassy concretions, produced at the time of the appearance 

 of the first oocytes. The whole vicinity of the gonadial tubes was 

 •crowded with leucocytes filled with large granules. It almost seems as 

 if the leucocytes were accumulating excretions from the gonads, but 

 •definite proof is lacking. 



Two New British Water-Mites 4 — C. D. Soar describes a new 

 genus Pseudofeltria, allied to Feltria, and Mideopsis crassipes sp. n. with 

 very thick legs. 



Minute Structure of the Tick.§ — Erik Nordenskiold fills some gaps 

 by a brief communication dealing with the alimentary system, excretory 

 organ, blood, and musculature of Ixodes reduvius. The intestinal 

 musculature, which previous investigators have missed, can be readily 

 seen in sections. The salivary glands show some remarkable cellular 

 peculiarities. The excretion in the lumen of the excretory organ occurs 

 in the form of drops and peculiar spherical granules of guanin. 



e. Crustacea. 



Rudimentary Gill in Astacus Fluviatilis.|| — M. Moseley describes 

 a minute rudimentary gill in A. fluvMilis Fabr., in a position which 

 appears to correspond to the arthrodial membrane of the seventh somite — 



that of the first pair of maxillipeds. It is not present in other species 

 of Astacus examined by the writer, e.g. .4. torrmtium, A. pallipes, 



or A. leptodactylus, nor in various related genera. It appears to be 



feebly represented in A. dauricus from Corea. 



Heteromorphism in Rock Lobster.^ — V. Ariola describes a case in 

 Palinurus vulgaris in which the left eye-stalk was represented by an 

 antenna-like structure, 16 centimetres in length. The regenerated struc- 

 ture resembled the exopodite of an antennule, but with more numerous 

 joints. He regards this as an atavistic reversion. But it is doubtful 

 whether the antennules are homologous with ordinary appendages. It 

 may be that the antennules and the eye-stalks are not strictly in line 

 with the appendages, or that one is and the other is not. 



Fresh-water Decapods of Celebes.**— J. Ptoux gives a detailed 

 comparison of the species of Caridiaa and of Potamon from this region, 

 together with notes on their distribution in the Malay Archipelago. 



* Biol. Centralbl., xxv. (1905) pp. 83-92 (3 figs.). 

 t Archives d'Anatomie Microscopique, i. (1897). 

 % Jouin. Quekett Micr. Club, ix. (1904) pp. 105-8 (2 figs.). 

 § Zool. Anzeig., xxviii. (1905) pp. 47S-85 (7 figs.). 

 || Quart. Journ. Micr. Sci., xlviii. (1904) pp. 359-6(5 (2 pis.). 

 •f Arch. Entwicklungsmechanik, xviii. (1904) pp. 248-52 (1 pi.). See Zool. 

 Zentralbl., xi. (1904) pp. 830-2. 



Revue Suisse Zool., xii. (1904) pp. 539-72 (1 pi.). 



*» 



