ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 473 



New Unstalked Crinoid.* — A. H. Clark describes Commissia pecti- 

 nifer sp. n. from Christmas Island. In this genus there are never more 

 than ten arms, the cirri are numerous, and the distal cirrus segments 

 (smooth in Gomatula) always bear spines or tubercles. The new form 

 differs somewhat abruptly from the others in the great length of the 

 teeth of the comb on the earlier pinnules, and by the large proportion 

 of pinnulars occupied by the conib. 



Ccelentera. 



Oogenesis in Pelagia.f — Julius Schaxel describes the process of 

 oogenesis in this jellyfish. The germ-cells are not at first distinguish- 

 able from the surrounding endodermic epithelium. There is no phago- 

 cytosis in the nutrition of the ovum. The processes that go on in the 

 oocyte are minutely described, emphasis being laid on the emission of 

 chromatin from the nucleus into the cytoplasm to form physiologically 

 essential " kinetochromidia." 



Fixation of Scyphistoma.J — F. Herouard finds that the pedal disc 

 of a polyp, once detached from its substratum, cannot be re-attached. 

 There is nothing of the nature of a sucker about the pedal disc. A 

 chitinous lamella is first formed by the ectoderm, and fits the substratum 

 exactly. Then very rapidly the ectoderm-cells also form numerous 

 " tonofibrils," and disappear as these are differentiated. Finally, only 

 tonotibrils are left between the chitinous lamella and the mesoglcea. 



History of Study of Coral-formations.§ — Siegmund Giinther gives 

 an interesting account of pre-Darwinian studies of coral-reef s and corals ; 

 dealing with the views and observations of De Castro, Pyrard, Marsigli, 

 Peysonnel, Spallanzani, Chamisso, and many others. 



New Genus of Antipatharia. — Kumao Kinoshita describes Hexa- 

 pathes heterosticha ' g. et sp. n. from Sagarni Bay. He refers it to the 

 Cladopathinge (= Schultze's Hexamerota), the third sub -family of 

 Antipathidge. The diagnosis reads : — Stem simple, with simple lateral 

 pinnules arranged in two longitudinal rows, and with simple branchlets 

 borne on the anterior surface of the stem ; spines of the axis short, 

 turned upwards, polyps elongated in the transverse axis ; mouth situated 

 on a high projection of the peristome ; stomodEeum long, reaching 

 nearly to the axis sheath ; sagittal tentacles given off from the level of 

 the lower end of the stoinodasum ; mesenteries six in number. 



Law of Budding in " Portuguese Man-of-war." f — 0. Steche has 

 introduced some order into the rather perplexing " Wirrwar " of zooids 

 in Physalia, and shows how the very aberrant arrangement of parts is 

 due to the development of the huge pneumatophore. This has led to 

 a shortening of the stem and an abandonment of the usual budding 

 zone. Steche notices in passing that Physalia has what other Siphono- 

 phores do not seem to have— a power of regenerating lost appendages. 



* Ann. Nat. Hist., vii (1911) pp. 644-5. 



t Festschrift Richard Hertwig, i. (1910) p. 167-212 (4 pis. and 2 figs.). 



J Bull. Soc. Zool., xxxvi. (1911) pp. 15-19 (3 figs.). 



§ SB. Bayer. Akad. wiss. Munchen, 1910, pp. 1-42. 



|| Annot. Zool. Japon., vii. (1910) pp. 231-4 (3 figs.). 



f Festschrift Richard Hertwig, ii. (1910) pp. 355-72 (10 figs.). 



