538 SUMMARY OF CURRENT RESEAECHES RELATING TO 



the geographical distribution, and a bibliography going back to 1542". 

 The family Bothriocephalidse s. str. is divided into three sub-families — 

 Diplogoninae, Mesogoninas, and Pleurogoninse. In the first the genital 

 apparatus is double in each proglottis, in the two other sub-families it 

 is single, but the opening is on the flat surface in Mesogoninfe and on 

 the lateral margin in Pleurogoninse. 



Rostellum of Davainea.* — Dr. A. Breazzano discusses the morpho- 

 logy of the rostellum, with special reference to Davainea cesticillus, D. 

 tetragona, and Cltapmania tauricollis. The rostellum in these forms is 

 represented by a bulb with a retiform content, and on this bulb there 

 are attached and distributed various muscular strands belonging to the 

 internal longitudinal system of the strobila. In short, there is a rudi- 

 mentary rostellum. 



Nemertea from Chili. \ — Dr. E. Isler finds that the Plate collection 

 of Nemerteans includes only Metanemertea and Haplonemertea, belonging 

 to the genera Eunemertes, Amphiporus, Tetrastemma, Eupolia, Lincus> 

 Cerebratulus, and Micrura. Five new species are included. 



Incertae Sedis. 



"Ciliated Urns" of Gephyreans. J — Ch. Gineste adopts for these 

 obscure elements the names Pompholyxia and Kunstleria, suggested 

 respectively by Fabre-Domergue and Delage, with the correlated 

 assumption of their parasitic nature. He doubts, however, the view 

 of Delage and others that they are to be regarded as Mesozoa, and 

 represent typical gastrulte. The occurrence, among the various methods 

 of reproduction, of a simple Protozoon type of division, leads him to 

 regard them as of Protozoon origin, but exhibiting many peculiarities 

 which are to be directly ascribed to the peculiar habitat. Jn another 

 note the author discusses the " enigmatical vesicles " found within the 

 general cavity of Phymosoma granulatum and other Sipunculids. These 

 occur together with typical forms of Pompholyxia and Kunstleria, and 

 the author brings forward evidence to show that they are a form of 

 Kunstleria, and give rise to the normal form by a process of alternation 

 of generations. 



Echinoderma. 



Development of Ophiura brevispina.§ — Caswell Grave finds that 

 this species is peculiarly favourable for the study of certain problems 

 connected with Echinoderm morphology, and that its larva is of the 

 remarkable type first figured by Krohn. The eggs are large, and at 

 first floating, but later the larvae become uniformly ciliated and are 

 capable of swimming below the surface. Gastrulation by invagination 

 does not seem to occur, but there is apparently a process of splitting 

 in an originally solid planula. The posterior enterocoeles are fused, 

 and the pouch so formed gives rise to the hydrocoele. The stone-canal 

 arises before the pore-canal, which is a remarkable reversal of the 



* Atti R. Accad. Sci. Napoli, xi. (1901) 7 pp. and 1 pi. 



t Zool. Jahrb., Supp. v. vol. ii. (1901) pp. 273-80. 



X Proc. Verb. Soc. Linn. Bordeaux, 1901. 10 pp. and 8 pis. 



§ Mem. Acad. Sci. Baltimore, viii. (1900) pp. 83-100 (3 pis.). 



