ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 999 



The second principal group of Acatarurnnia includes the families 

 Semseostomese and Bhizostomese. These are characterized by the 

 absence of septal knots, by the presence of broad coalesced regions 

 between eight radial and eight intermediate canals, and the conse- 

 quently different character of the peripheral gastro-canal system. 

 An important characteristic also consists in the development of the 

 four oral arms round the mouth. 



Ontogeny of Cubomedusse.* — Dr. W. Haacke's observations on 

 the development of the Cubomedusaa were made on a new species 

 found in the Gulf of St. Vincent, South Australia — Cliarybea Bastonii. 

 Hackel appears to be right in asserting, and Claus wrong in denying 

 that there is an alternation of generation. Dr. Haacke observed in 

 his smallest specimen a stalk-canal traversing the aboral gelatinous 

 disc, by which the gastro-canal system of the young Medusa might be 

 connected with a nurse-polyp (Scyphostoma ?). The young Medusa has 

 a strongly pyramidal umbrella, and so approaches the Tessera and the 

 Scyphostoma form. 



With regard to the sensory knobs it was observed that the species 

 had only two unpaired eyes of unequal size, and both axial in position. 

 They had no vitreous body in the adult, though the young has a 

 structure which may be regarded as such ; the young has, moreover, 

 four paired eyes. The velar canals are primitively unbranched. 



Formation of a new stalk in Tubularia.f— Dr. H. Klaatsch de- 

 scribes a curious case of abnormal formation of a fresh stalk on the 

 polypes of Tubularia mesembryanthemum. The polypes, captured at 

 Trieste along with others perfectly normal, exhibited a blind process 

 springing from the region where the stalk passes into the hydranth. 

 The process was histologically a stalk, and not a special organ or 

 cnidophor. Why this secondary stalk should have resulted, Dr. 

 Klaatsch does not attempt to suggest. 



Clavularia viridis.J — Dr. S. J. Hickson has a preliminary note on 

 this anthozoon, the structure of which shows it to be allied to the extinct 

 Syringopora. Both these genera are almost certainly Alcyonaria. 

 The young colonies resemble Comularia, the adult, Tubipora. Herein 

 the author finds evidence to support his already expressed view that 

 Tubipora should be united with the Cornulariidas into a group of 

 Stolonifera ; Clavularia is, in fact, a connecting link. 



Anatomy of the Madreporaria.§ — In his second contribution to 

 this subject Mr. G. H. Fowler deals with two colonial perforate forms, 

 Madrepora Durvillei and M. aspera. The former species presents 

 interesting features common to it and the Alcyonaria; there is a 

 marked tendency to an absence of polyps from one (the ventral) side 

 of the branch and branchlets ; the axial and abaxial septa are strongly 

 developed, and there is a concomitant bilateral symmetry ; there is the 



* Zool. Anzeig., ix. (1886) pp. 554-5. 



t Arch. f. Mikr. Anat., xxvii. (1S86) pp. 632-50 (1 pi.). 



X Proc. Roy. Soc, xl. (1886) pp. 322-5. 



§ Quart. Joum. Micr. Sci., xxvii. (1886) pp. 1-16 (1 pi.). 



