1010 SUMMARY OF CURRENT RESEARCHES RELATING TO 



hydropliyllium, wliicb. is free on either side ; near the end of the 

 primitive cavity there is a spherical organ, which is the future float ; 

 it is inclosed by a layer of hypoblastic cells. The primitive hydro- 

 phyllium is supposed to pass, " by a few modifications in its external 

 contour, into some other organ, probably a differently formed covering 

 scale." 



Cyclical Development of Siphonophora.* — Prof. C. Claus criti- 

 cizes the results of Chun on the development of certain Siphonophora. 

 In a recent work Dr. Chun has stated that in Monophyes irregularis 

 and M. gracilis the primary swimmiiig-bell falls off and is replaced 

 by a second, and that this fact is against Claus's view that Muggisea 

 Kochii is not a Monophyid but a Diphyid. If the swimming-bell of 

 MonopTiyes irregularis and M. gracilis, both undoubtedly Monophyids, 

 corresponds to a second heteromorphic bell, the young form of 

 Muggisea with a primary bell cannot be a Monophyid. The question 

 is gone into in considerable detail, and Claus points out that an 

 animal without mouth or alimentary canal could hardly conceivably 

 be the "nurse" of a future generation, but is evidently merely an 

 immature form. 



Structure ofVelella.f — M. Bedot has already contributed a short 

 paper upon this subject, which has been noticed in this journal. | The 

 present communication is an extension of some of the results formerly 

 obtained. The " central organ " in the adult Velella is surrounded 

 by a vascular zone, on which are attached the gasterozoids ; this zone 

 is absent in the young, where the central organ is present as a small 

 mamilla; its lower surface is almost entirely occupied by the 

 central gasterozoid ; above it, as in the adult, is a layer of epi- 

 thelium which lines the pneumatophore. The canals have a regular 

 symmetrical disposition, and communicate with the central gastero- 

 zoid by five secondary canals. The greater portion of the central 

 organ is formed by a mass of cnidoblasts. The pneumatocyst is 

 divided up into a number of chambers, which send off diverticula into 

 the central organ. 



New ]V[inyas.§ — Prof. F. J. Bell explains that a justification is 

 to be found for describing a single new species of Minyas, M. torpedo, 

 in the rarity of members of this interesting group of floating Anthozoa, 

 very few being found by the ' Challenger ' (or, it may be added, by 

 the German corvette ' Gazelle '). The morphological interest of the 

 species lies in the fact that it makes yet another exception to the rule 

 that the Actiniaria in their adult state present a hexamerous arrange- 

 ment of their parts. 



Metamorphosis of Bolina Chuni.|| — Dr. E. v. Lendenfeld describes 

 the postembryonal development of this new species of Ctenophora, 

 one of the few species of Ctenophora found in Australian waters. 



* Zool. Anzeig., viii. (1885) pp. 443-8. 



t Eecueil Zool. Suisse, ii. (1885) pp. 237-51 (1 pi.). 



X See this Journal, iv. (1884) p. 576. 



§ Jonrn. Linn. Soc. Lond., xix. (1885) pp. 114-6. 



II Proc. Linn. See. N. S. Wales, ix. (1885) pp. 929-31 (2 pis.). 



