ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 457 



tion in structure or origin between gut and mesenchyme. There is 

 no trace of endodermic primordium, not even of the four transitory 

 endodermic cells which are seen in Triclads. 



New Species of Rhynchodemus.* — W. E. Bendl gives a descrip- 

 tion of two new Planarians in this genus — R. henrici (European) and 

 R. purpureas (East African). He calls attention to the very varied 

 states of the male genital apparatus in different species — from great 

 simplicity in R. ochroleucus, to relative complexity in R. henrici — and he 

 finds that the forms with simple copulatory apparatus are oriental and 

 Australian, while those with complex parts are paltearctic and Ethiopian. 

 He takes a survey of the known forms, and arranges them in order of 

 differentiation. 



Stichostemma Eilhardi.f — Charles Perez found in a garden tank at 

 Bordeaux specimens of this fresh-water Nemertean, which was discovered 

 by F. E. Schulze in an aquarium in the Zoological Institute at Berlin, 

 in 1893, and studied by T. H. Montgomery. Perez notes that the 

 number of eyes is variable, and that protandrous hermaphroditism is 

 very marked. 



Incertse Sedis. 



Structure of Echinoderidae.J — A. Schepotieff re-affirms, in answer 

 to Zelinka, his previous statements as to the structure of these peculiar 

 forms. He regards the Echiuoderidre as related to Gastrotricha on the 

 one hand, to Gordiacea and Nematodes on the other. 



Lower Silurian Brachiopods.§— F. Schmidt discusses a number of 

 forms from the Eastern Baltic, chiefly from Lower Silurian strata, be- 

 longing to the genera Plectambonites Pand., Leptcena Dalm., and Stro- 

 phonema Blainv. 



Brachiopod Homoeomorphy.||— S. S. Buckman points out that it is 

 easy but dangerous to group under one name a series of shells of similar 

 appearance, especially when they are in the smooth catagenetic stage, 

 because this smooth stage may have been attained by the loss of different 

 distinctive features, pointing to polygenetic origins. An instructive case 

 in this respect is found in the series of forms called Spirifer glaber, a 

 heterogeneous series, including representatives of at least three genetic 

 series, as the author shows. 



North American Incrusting Chilostomatous Bryozoa.1T — Alice 

 Robertson deals with 45 species (in 18 genera) of incrusting Chilo- 

 stomata from the west coast of North America. Of these species six 

 are new. Some of the descriptions given by Hincks (from scanty 



* Zeitschr. Wiss. Zool., lxxxix. (1908) pp. 525-54 (2 pis.). 



+ C.R. Soc. Biol. Paris, lxiv. (1908) pp. 476-7. 



% Zool. Anzeig., xxxii. (1908) pp. 585-9. 



§ Bull. Acad. Imp. Sci. St. Petersbourg, 1908, pp. 717-26. 



11 Quart. Journ. Geol. Soc, lxiv. (1908) pp. 27-33. 



«[f Univ. California Publications (Zoology) iv. pp. 253-344 (11 pis.). 



