312 SUMMARY OF CURRENT RESEARCHES RELATING TO 



lateral ambulacra are directed forwards, and not at right angles to the 

 long axis of the test ; there is an open circumanal fasciole as in Metalia. 

 This last feature has generally been regarded as a recent acquisition ; 

 its co-existence with the archaic position of the apex is of interest. 



Regeneration in Starfish.* — Sarah P. Monks, in studying regenera- 

 tion of Phataria (LincJcia) fascialis, cut arms at different distances from 

 the disc, and a number of the single rays produced new bodies, while 

 the rest of the star-fish produced a new ray. There was little difference 

 i m the rate of growth of each. The cut edges heal and draw clown 

 towards the oral side of the starfish, then small knobs appear at the 

 end, which grow into rays in which the ambulacra! furrow soon appears, 

 with the small mouth in the centre of the rays. 



Coelentera. 



Devonian Medusa.f — F. Kinkelin gives a description of Broohsella 



rhcnana sp. n., closely allied to Walcott's Broohsella alternata from the 

 middle Cambrian. Kinkelin's discovery is of special interest because 

 it is the first Medusa found in the Devonian. It was found near 

 Laurenburg on the Lahn, by Ludwig Petry. 



New Cerianthid.J — L. Roule describes Pachycerianthus benedeni. 

 The mesenteries are short, only two reaching the base ; the directive 

 mesenteries are thick, giving the directive chamber the form of a 

 cvlindrical tube ; there is an alternation of fertile mesenteries with 

 acontia and sterile mesenteries without acontia, but with mesenteric 

 filaments ; the endodermic musculature is scarcely developed ; the wall 

 of the column is thick and substantial owing to the development of the 

 longitudinal musculature and the mesogloea. Apart from the size of 

 the single specimen (British Museum) and the number of mesenteries, 

 there is a suggestion of the characters of the acontiferous larval forms 

 of Cerianthids. It seems, therefore, that there are non-tubicolous 

 Cerianthids, free-living for at least a large part of their life, which 

 retain some of the larval characters of the ordinary tubicolous types. 

 Roule also notes that there is a marked resemblance between Pachy- 

 c&riantlms and some Antipatharia, especially Stichojmthes. 



Porifera. 



Spermatogenesis in Porifera and Ccelentera.§ — W. Gorich finds 

 that there is a close correspondence in the spermatogenesis of Spongilla 

 fluviatilis and Amelia aurita. In both, the central corpuscles give rise 

 to the intra- and extra-cellular axial filament and to the middle-piece of 

 the ripe spermatozoon. In both, there is a typical apical portion, and 

 the long tail is formed from the protoplasm of the spermatid. The 

 general result is to show that the processes of spermatogenesis in the 

 lowest Metazoa are closely parallel to those in higher forms. Some 



* Proc. Acad. Nat. Sci. Philadelphia, It. (1903) p. 351 (1 fig.). 



t Ber. Senckenberg. Nat. Ges., 1003, pp. 89-96 (1 pi.). 



t Comptes Rendus, cxxxviii. (1904) pp. 708-10. 



§ Zeitschr. -wise. Zool., Ixxvi. (1904) pp. 522-43 (1 pi. and 4 figs.). 



