30 SUMMARY OF CURRENT RESEARCHES RELATING TO 



regular row, Sanguinicola ormata, g. et sp. n. ; the other, which is more 

 common, is without hooks, S. inermis, sp. n. They are the type of a 

 new family, Rhynchostomida, whose diagnosis is as follows. Rhabdo- 

 ccelida with pharynx entirely reduced ; at end of straight foregut are 

 4-6 large cseca in a rosette formation. Mouth at the tip of the 

 proboscis-like anterior end. Two sex openings present, ovaries 

 distributed over the greater part of the body, surrounding the testes 

 which are limited to a medium strip. The copulatory organ is reduced 

 to a blunt papilla. The brain is absent ; so also are sense-organs. 

 There are two longitudinal nerve-trunks with an anterior commissure. 

 The excretory pore is at the hinder end ; the two main lateral trunks 

 unite into a single short exhalant duct. 



Migrations of Planarians in Mountain Streams.* — Walter Voigt 

 continues his studies on the distribution of species of Planaria in the 

 mountain streams of Rheinland. He distinguishes (a) migrations of 

 individuals, both occasional and periodic, and (I)) gradual alterations in 

 progress since the last glacial epoch in the distribution of particular 

 species. The factors prompting migration are discussed in detail, e.g. 

 the search that a species makes for its particular optimum temperature. 



Effect of Starving on Planarians.f — F. Stoppenbrink has made 

 some interesting experiments on fresh-water Triclads, e.g. Planaria 

 gonocephala, P. alpina, Dendrocnlum lacteum, and Polycelis nigra. 



The effect of reduced nutrition is seen externally in reduction of 

 size and change of form. Gradually all the cells become smaller, the 

 dispensable organs degenerate and disappear. There is no great disrup- 

 tion in the nervous, alimentary, and excretory systems, or in the paren- 

 chyma, musculature, and epithelium, but the gonads undergo total 

 degeneration, first the yolk-glands, then the copulatory apparatus, 

 finally the ovaries and testes. There is no phagocytosis. The involu- 

 tion of the genital system is in the inverse order of its development. 



Sexual Organs of New Polyclad Genus.J — E. M. Herzig describes 

 the genital organs in Laidlawia trigoitopora g. et sp. n., whose configura- 

 tion presents certain peculiarities. There are five pairs of ovaries and 

 an accessory female genital pore, which opens near the posterior end on 

 the dorsal side, leading into a bursa in which sperms were found. 



Terrestrial Planarians.§ — Bruno Busson gives an account of the 

 structure of Pelmatoplana willeyi sp. n., from Loyalty Islands, and 

 some South American species of Geoplana. 



Parasites of Fishes. || — Jas. Johnstone reports on various internal 

 parasites and diseased conditions in fishes. He discusses Distomum 

 {?) valdeinflatum Stossich, from the muscles of Phuronectes limanda ; 



* Verh. Nat. Ver. Rheinland, lxi. (1905) pp. 103-78. 



t Zeitschr. wiss. Zool., lxxix. (1905) pp. 496-547 (1 pi. and 1 fig.). 



\ Zool. Anzeig., xxix. (1905) pp. 329-32. 



§ SB. Akad. Wiss. Wien, cxii. (1903, received 1905) pp. 375-429 (1 pi. and 5 figs.) 



II Trans. Liverpool Biol. Soc, xix. (1905) pp. 278-300 (4 pis. and 5 figs.). 



