50 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Polychsets correspond to the head-segments of other Polychtets. The 

 post-thoracic segments represent differentiated abdominal segments or 

 ordinary trunk segments. 



Antarctic Species of Phascolosoma.* — W. F. Lanchester describes 

 P. socium sp. n., a Sipunculid presenting in the main the chief features 

 of the P. margaritaceum group. 



New Deep-sea Echiurid.f — Iwaji Ikeda describes Protobonellia 

 mitsulcurii g. et sp. n., from Sagami Bay. The proboscis is long and 

 tubular, not bifid. The body has two distinct ventral hooks, without 

 anal spine. There is a single genital duct with a long-stalked and 

 fimbriated funnel. The anal glands are once branched before ending 

 in ciliated funnels. The eggs have a nutritive cell-mass, appearing, as 

 in Bonellia, like a cone at one pole. The alimentary canal and blood- 

 vessels are well developed. The new genus is nearly related to Bonellia, 

 but more primitive. 



Penis of Criodrilini.l — Luigi Cognetti de Martiis gives a detailed 

 account of the so-called "penis" in Alma and Criodrilus, devoting 

 particular attention to the vascular supply and the glandular differentia- 

 tion. He does not think that the penis has anything special to do with 

 respiration (as has been suggested), but that is specialised in connection 

 with copulation, and, perhaps, with the formation of the envelope of the 

 spermatophores. 



New Leech. § — Ernest E. Hemingway describes Placobdella pediculata 

 sp. n . from the isthmus or shoulder of the sheepshead (Aplorfiaotus 

 grunniens) in Lake Pepin, Minnesota. , As the attachment continues, 

 the inflamed tissues of the host grow up like a collar, and close in 

 around the body of the leech in front of the collar. The most striking 

 external peculiarity is the attenuation of the posterior somites to form a 

 narrow pedicel just in front of the posterior sucker, which consequently 

 stands out freely in a most characteristic manner. 



New Myzo3toinum.|] — Rudolf Ritter von Stummer-Traunfels 

 describes a new species of Myzostomum (M. antarcticum) on Antedon 

 adriani, a new Crinoid found by the ' Discovery ' in the Antarctic. He 

 also reports from the same host another species, M. cysticolum, which 

 has been previously obtained in Ross's Sea in the Antarctic, off the east 

 coast of Japan, and in the Tropical West Atlantic — a fine instance of 

 wide distribution, which finds explanation in the antiquity of the group 

 and in the uniformity of deep-water conditions. The southern range of 

 the Myzostomidas has been extended by these discoveries. 



Nematohelminthes. 



Notes 021 Nematodes. IF — Fayet and Moreau Q-ive an account of 

 Filaria initials (discovered in 1868 by Rivolta), which occurs in the 



Nat. Antarctic Exped. (Zool.) iv. (1908) 6 pp. 



Armot. Zcol. Japon, vi. (1908) pp. 259-65 (4 figs.). 



Atti R. Accad. Sci. Torino, xliii. (1908) pp. 1122-37(1 pi. and 1 fig.). 

 § Amer. iNat., xlii. (1908) pp. 527-32 (3 figs.). 

 II Nat. Antarctic Exped. (Zool.), iv. (1908) 26 pp. (1 pi.). 

 i C.R. Foe. Biol. Paris, lxiv. (1908) pp. 10-11. 



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