422 SUMMARY OF CUEEENT EESEAECHES RELATING TO 



New Rhabdoccele Turbellarian. * — Prof. W. A. Haswell describes, 

 as Didymorchis paranephropis g. et sp. n., a Turbellarian found in the 

 branchial chambers of the New Zealand crayfish (Paranephrops neozela- 

 nicus). Its most striking characters are the following : — The pharynx 

 is of the type called by Von Graff a pharynx doliiformis ; there are 

 two excretory apertures near the mouth, and a single reproductive 

 aperture ; the ovary is single and compact, and there are two elongated 

 vitelline glands ; there is no bursa copulatrix, and the paired testes are 

 compact ; the penis is complex and chitinous. The animal appears^ to 

 spend its whole life in the crayfish's gill-chambers, the eggs being 

 attached singly to the epipodites. There is no metamorphosis in 

 development, the young being like the adult when hatched. The animal 

 appears to be nearest the Vorticida, but is not related to Anoplodium 

 and Graffilla, the already known parasitic forms of that family. 



Incertae Sedis. 



Life-History of Orthonectids.f — M. Caullery and F. Mesnil dis- 

 tinguish the sexual plasmodial stages — which move by pseudopodia. 

 multiply by division, and propagate the parasitic infection — from the 

 sexual ciliated stages, to which the former give origin endogenously. 

 Metchnikoff found that some plasmodial forms of Bhopalura intoshi were 

 hermaphrodite ; this is general in Bh. metchnikovi, and probably also in 

 Bh. julini. The authors confirm Koehler in finding rare hermaphrodite 

 forms of Bh. ophiocomse. The development of the ciliated sexual forms- 

 does not seem to proceed directly within the parasitic plasmodial forms 

 in their original hosts ; it is probable that the ripe forms escape into 

 the sea, that fertilisation occurs there, that a fresh infection occurs, and 

 that then the ciliated forms begin to appear within their plasmodial 

 parents. The dimorphism of females indicated by Julin seems to have 

 been somewhat exaggerated, and the authors find intermediate forms. 

 They find no reason to believe that the one type of female gives origin 

 to males and the other type to females. 



Development of Phoronis.J— Dr. A. T. Masterman discusses some 

 points at issue between himself and Prof. Eoule. He reaffirms his 

 conclusions as to the origin of the mesoderm from paired hypoblastic 

 ingrowths, and is of ojfinion that Eoule furnishes no valid evidence for 

 the theory of a mesenchymatous origin. He further rebuts the imputa- 

 tion of error in regard to his descriptions of such larval organs as 

 mesenteries, dorsal vessel, tic, and suggests that there may be con- 

 siderable differences between the two larvse studied respectively by 

 himself and Eoule. Masterman further entirely rejects Eoule's hypo- 

 thesis of the relation of the Actinotrocha to the trochophore, and of 

 the latter to the Vertebrate embryo. 



Rotatoria. 



Specific Characters of Asplanchna intermedial — C. F. Eousselet 

 has published an account of this hitherto insufficiently characterised 



* Proc. Linn. Soc. N. S. Wales, xxv. (1900) pp. 424-9 (2 pis.). 



t Compte3 Rcndus, cxxxii. (19U1) pp. 1232-4. 



: Zool. Anzeig.. xxiv. (1901) pp. 228-33. Cf. this Journal, ante, p. 15S. 



§ Journ. Quek. Micr. Club, viii. (1901) pp. 7-12 (1 pi.). 



