ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 51 



the vascular diverticula of the tentacles, the bod y-cavity and the gonads. 

 It is also oscillatory in the small circular vessel at the base of the 

 tentacles. 



Reproduction may take place throughout the year, but is much more 

 marked in the summer months. This species does not die off annually. 



New Species of Alcyonidium.* — 0. Roehrich describes Alcyonidium 

 topsmti sp. u., thrown up on the shore at Luc-sur-Mer. It somewhat 

 resembles A. gelatinosum, but its surface is covered with fine asperities, 

 and the zocecial orifice is bi-labiate. In A. albidum the orifice is trilobed. 

 and Roehrich proposes to modify the definition of the genus Alcyonidium 

 to include these two labiate species. In the other species the orifice is 

 simple and papilliform. 



Growth and Habits of Biporae.f — C. M. Maplestone thinks that the 

 conical Biporre in their living state have the base uppermost. All of 

 them have on the apex small avicularia and pores, and the author con- 

 siders that from these pores there grow out filaments similar to those 

 recorded by Whitelegge on Bipora philippinensis, and probably attach 

 themselves to fragments of shells, etc., on the surface of the ocean-bed, 

 and so anchor themselves. He discusses the somewhat enigmatical 

 " semi-lunar slits," and indicates his view that they do not indicate the 

 commencement of new zocecia. 



Maplestone also describes} an interesting massive Polyzoon — Gellepora 

 rerticalis sp.n. — from the South Australian coast, and a noteworthy 

 species, § Parmularia obliqua McG., which has a flexible stem or filament 

 6-7 cm. long and 2 mm. thick. 



New Mesozoon.|| — Olaw Schroder describes Buddenbrockia pluma- 

 tellse ^.etsp.n. found by von Buddenbrock in colonies of Plumatella 

 repent. The stage found in the body- cavity of Plumatella was worm- 

 like ; the largest were 1*5 mm. in length by 0" 08-0*1 mm. in breadth. 

 There are two layers of cells and a lumen. In older stages the inner 

 layer changes greatly and gives rise to an oogonial layer, producing ova. 

 These seem to develop parthenogenetically into oval embryos. The 

 author indicates the resemblances between this parasite and Orthonectids 

 and Dicyemids, but thinks that it must in the meantime remain un- 

 attached. It is the first " Mesozoon " from a fresh-water animal. 



Echinoderma. 



Echinoderms of Peru.^f — H. L. Clark reports on a collection from 

 Peruvian coasts. There are no Crinoids known from the region. There 

 are only seven Holothurians and ten Ophiuroids. The Echinoids are 

 represented by a dozen species, and the starfishes by twice that number. 



It is interesting to note that the Peruvian marine fauna is made up 

 of two quite different elements, that from the Panamic region and that 



* Arch. Zool. Exper., v. (1910) Notes et Revue, No. 6, pp. clxiv-viii (3 figs.), 

 t Proc. R. Soc. Victoria, xxiii. (1910) pp. 1-7 (1 pi.). 



J Tom. cit., pp. 39-41 (3 pis.). § Torn, cit., pp. 42-3 (1 pi.). 



|| Zeitschr. wiss. Zool., xcvi. (1910) pp. 525-37 (2 pis. and 4 figs.). 

 i Bull. Mus. Comp. Zool. Harvard, lii. (1910) pp. 321-58 (14 pis.). 



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