674 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Notes on Convoluta roscoffensis Graff.* — E. Warren has made the 

 interesting" discovery of the presence of Convoluta roscoffensis at Scotts- 

 burg, on the Natal coast. They have been found occupying an area of 

 a few hundred yards only, and have not been discovered, though looked 

 for, elsewhere. On the circumscribed area they were present in large 

 numbers, giving the sand a bright green tint. Some observations have 

 been made upon the ova, which, during their growth and maturation, 

 are remarkable for their branched or stellate condition — they are 

 probably sending out pseudopodia into the surrounding parenchyma, for 

 there are no follicle cells. 



Triclad Studies.f — L. Bohmig gives a systematic and anatomical 

 account of the families Procerodidae and Bdellouridas. This embraces 

 diagnostic descriptions of the families, sub-families, genera, and species, 

 with lists of synonyms, so that there is a satisfactory clearing of the 

 ground in this field. The anatomical account is also comprehensive ; 

 the nervous system (including sense organs) and the genital system in 

 particular are exhaustively discussed. 



Fresh-water Species of Polycystis. % — E. Bresslau describes 

 Polycystis goettii sp. n. from a pond in the botanic garden at Strassburg. 

 It is particularly interesting as being, like Du Plessis' Macrorhynchus 

 (Phonorhynchus) Umanus, a fresh-water representative of a marine 

 genus. 



Maturation and Fertilisation in Thysanozoon brocchi.§ — R. 

 Schockaert describes the origin of the male pronucleus and the appear- 

 ance of a peculiar transient " spermocentre." As the female pronucleus 

 is formed, the ovocentre disappears. The centrosomes of the first cleav- 

 age seem to be new formations, and so do those of the second and third 

 cleavage. 



Nervous and Excretory Systems of Freshwater Triclads.|| — H. 

 Micoletzky describes in species of Planaria, Polycelis, etc. the minute 

 structure of the " brain," which is composed of three pairs of ganglia 

 with three commissures, and the general structure of the excretory 

 canals. 



Bathypelagic Nemertines.l — L. Joubin calls attention to ten new 

 species of bathypelagic Nemertines collected by the Prince of Monaco off 

 the Azores and Canaries and in the Sargasso sea. There are six new 

 species of PlanMonemertes, three of Nectonemertes, and one of Pelayo- 

 nemertes, the descriptions of which will be published later. 



Incertee Sedis. 



Ordovician and Silurian Bryozoa.** — Ray S. Bassler has revised the 

 large collection made by U. P. James and described by him and his son, 



* Annals Natal Government Museum, i. (1906) pp. 105-8 (1 pi.). 

 t Zeitschr. wiss. Zool., lxxxi. (1906) pp. 344-504 (8 pis. and 9 figs.). 

 X Zool. Anzeig., xxx. (1906) pp. 415-22 (5 figs.). 

 § La Cellule, xxii. (1905) pp. 1-37 (3 pis.). 

 || Zool. Anzeig., xxx. (1906) pp. 702-10 (4 figs.). 

 f Comptes Rendus, cxlii. (1906) pp. 1349-51. 

 ** Proc. U.S. Nat. Mus., xxx. (1906) pp. 1-66 (7 pis.). 



