ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 321 



more or less rare, and all of more than ordinary biological interest. 

 He describes Pachycordyh weismanni, sp. n., and notes, inter alia, that 

 in the females (which alone were found) the germ-cells originate in the 

 endoderm and do not occur elsewhere at any time during their growth 

 or maturation. The medusoid is either extremely degenerate, or one of 

 very primitive type. Its development within a chitinous capsule 

 (gonangium ?) associated with the sporosac-like history of the gonophore. 

 would seem to suggest the latter alternative. The development of 

 Anthomedusas within gonangia is quite rare, if not wholly anomalous. 



The oogenesis, maturation, and fertilisation in Tubular ia mesembry- 

 anihemum Allm. are then described. The germ-cells were found both in 

 the ectoderm of the peduncle of the gonophore, as Brauer contends, 

 and in the ectoderm and endoderm of the spadix, as Ciamician and 

 Weismann reported. An account of the cleavage, the germ-layers, and 

 the embryo is given. 



The author also describes Perigonimus napolitanus, sp. n. (?), 

 Gemmaria implexa Alder, Corydendrium parasiticum Cavolini, and 

 Podocoryne conchicola (Philippi), and supplies numerous contributions 

 towards a clearer knowledge of some disputed problems concerning the 

 Hydromedusae. 



Regeneration and Non-Sexual Reproduction in Sagartia.* — R. B. 

 Torrey and J. R. Mery describe the different modes of fission observed 

 in 8. davisi. They endeavoured experimentally to discover the cause of 

 fission. A complete answer has not been found, though they conclude 

 that an interruption of the physical continuity of two portions of a 

 polyp by a cut in the normal fission plane tends to interfere with the 

 physiological inter-action of the separated regions, and to initiate the 

 process of fission. 



Chilian Actiniae.! — J. Playfair McMurrich reports on L. Plate's 

 collection of Actinians from the coast of Chili. He divides the 

 simpler Actinians into families, recognising in addition to the Edwards- 

 id a3, which will include the Edwardsiae, HalcampidaB, and the genus 

 Scytophorus, the Gonactiniidas, which will include Gonactinia, Protanthea, 

 and possibly Oractis, the Peachiida3, including Peachia, Eloactis, and 

 Haloclava, and the Ilanthidfe, having essentially the limitations 

 recognised by Andres. Altogether 27 species are dealt with. 



The Mesenteric Musculature of Actiniaria.J — 0. Carlgren con- 

 tributes some details regarding these muscles and their homologies. 

 One or two of his points may be given. The basilar muscles arise in 

 the Actiniaria later phylogenetically than the parieto-basilar and the 

 parietal muscles. The lower Actiniaria (Protanthea, Athenaria, and the 

 Discosomidea among the Stichodactylineae) have in their mesenteric 

 musculature no homologue to the basilar muscles, which develop only 

 with the growth of a true creeping base. In the Athenaria the parietal 

 muscle which is found on the same side as the transverse mesenterial 

 muscles is homologous with the parietal basilar muscle of the higher 



• Univ. California Publications, i. (1904) pp. 211-26. 



t Zool. Jahrb., Supplementband vi., Fauna Chilensis, 1904, pp. 215-306 (6 pis. 

 and 5 figs.). % Zool. Anzeig., xxviii. (1905) pp. 510-19. 



June 21st, 1905 z 



