294 SUMMARY OF CURKENT RESEARCHES RELATING TO 



Minute Structure of Planaria polychroa.* — Paul Lang adds to 

 our knowledge of this Turbellarian, dealing with the minute structure 

 of the gut, the excretory system, the nervous system, the sense-organs, 

 and the gonads. 



Structure of Cephalothrix.f — Gerarda Wijnhoff sums up the 

 characteristic features in the structure of Cephalotrichidse. The body- 

 wall consists of a single layer of epithelium, the basal membrane, a thin 

 outer layer of circular muscle, and an inner longitudinal muscle layer. 

 An inner circular layer is present in ProcephaJothrix, absent in Cephalo- 

 tricheUa and Cephalothiix. There is no muscle cross. The rhyncho- 

 coelom musculature is quite separate from the body musculature. Brain 

 and lateral strands lie in the inner longitudinal layer ; there are four 

 strong head-nei'ves. The vascular system consists of two longitudinal 

 vessels, which communicate only at the tip of the head and the end of 

 the tail. There are numerous nephridia. The only sense-organs known 

 are the epithelial eyes. The position of the family among Nemertines, 

 and the general relationships of the various families of Nemertines, 

 form the main subject of the paper. 



Rotatoria. 



• New Genus of Rotifer. J — R. Lucks describes Hyalocephalus trilobus 

 g. et sp. n. from a moor near Berent. The body has the typical structure 

 of Floscularids. The head, seen from above, is triangular with re-entrant 

 margins and rounded corners ; it is thick and cushion-like. Tht; cingu- 

 lum is a broad band of cilia extending round the margin of the head. 

 The animal is viviparous. 



Coelentera. 



Development of Alcyonium digitatum.§ — Annie Matthews found 

 segmenting ova from January 27 to February 2. She observed morulse, 

 spherical ciliated planulae, oval planulte, pear-shaped larvae, fixation, 

 shrinkage along the long axis, invagination of the ectoderm to form the 

 stomodaeum, and the appearance of the tentacles. 



Protozoa. 



New Division of the Protozoa. || — Casimir Cepede regards the 

 Cnidosporidia and the Acnidosporidia as Rhizopods adapted to parasitic 

 life. He proposes a division Cytopleurosporea defined by the occurrence 

 of a spore with a cell- wall, a schizogonic cycle, and a gamogonic cycle 

 preceding sporulation. The division should be ranked near the Lobosa, 

 from which it has been derived by parasitism. The author favours the 

 view of Leger and Duboscq that the Sporozoa must be broken up. 



* Zeitschr. wiss. Zool., cv. (1913) pp. 136-55 (1 pi. and 1 fig.). 



t Zool. Jahrb., xxxiv. (1913) pp. 291-320. 



X Zool. Jahrb., xxxiv. (1913) pp. 321-40 (1 pi. and 2 figs.). 



§ Journ. Marine Biol. Assoc, ix. (1913) pp. 359-60. 



\ Comptes Rendus, clvi. (1913) pp. 574-6. 



