ZOOLOGY AND BOTANY, MIOKOSCOPYj ETC. 47 



longer be associated with the MoUusca, now that Caldwell has shown 

 that the epistome of Plioronis is the modified prseoral hood of the 

 actinotrocha-larva. But this is a certainty with regard to Phoronis, 

 but by no means so with regard to Bhdbdopleura, the development of 

 which must be studied before we can say certainly whether Allman 

 is right in regarding the buccal-shield of BJiahdopleura as repre- 

 senting the mantle-area of Lamellibranchs, and whether it and Cepha- 

 lodiscus are not degraded Lamellibranchs, The author suggests some 

 questions to future students of this enigmatic form. 



New Species of Paludicella.* — E. Potts describes a new species 

 of Paludicella (P. erecta). The genus has heretofore contained only 

 the single clearly defined species P. Ehrenhergi. The present form 

 is strikingly different from the old one, both in the number of its 

 ciliated tentacles and in the character of the coenoecial cells. The 

 form was first noticed in a small stream, perhaps 50 feet above tide- 

 water. A few days after, it was gathered within tidal limits near 

 Philadelphia. In the creek, it was found most abundantly in the 

 pools amongst the rapids, frequently covering the upper surface of 

 stones at the depth of a foot or more to the extent of many square 

 inches. The erect portions of the coenoecial cells in the denser parts 

 of the colonies are about a line in height, and standing very closely, 

 suggest a comparison with the surface of a chestnut-bun. In the 

 river they were found penetrating the masses of incrusting sponges, 

 particularly Meyenia Leidyi. " The nearly simultaneous observation 

 of this species in three distinct localities, together with its abundance 

 in each, indicate that it is probably not uncommon, and excites 

 surprise that it does not appear to have been previously noticed." 



' Challenger ' Polyzoa.f — The description of the Polyzoa collected 

 during the expedition of the ' Challenger ' was undertaken by Mr. 

 G. Busk, and the first part of his Eeport, comprising the Cheilosto- 

 matous forms, or those in which the mouth of the zooecium or cell is 

 provided with a movable lid which shuts down over the polypide when 

 retracted, has just been published. 



The number of species is 286, and when these came into Mr. Busk's 

 hands he found no less than 180 of them new. In one genus alone, 

 that of the BeteporcB, the number of known species has been raised 

 from 31 to between 50 and 60. 



Among the most important contributions of the Report to the 

 systematic zoology of the Polyzoa is the revision which it contains 

 of Adeona and allied genera. A critical comparison of the species 

 ^of Adeona with species belonging to other genera which had been 

 hitherto placed among the Escharidce. has necessitated the founding 

 of a new family, Adeonege, in order to include the whole in a single 

 natural group. This family has several peculiarities, among which the 

 most interesting is the possession by all the species of three different 

 kinds of cells, which the author terms zooecial, ooecial, and avicularian. 



* Proc. Acad. Nat. Sci. PMlad.. 1884, pp. 213-4. 



t Zoology of the Voyage of H.M.S. ' Challenger,' xxx. '' Keport on the 

 Polyzoa — the Cheilostomata," 216 pp. (^36 pis.). 4to, London, 1884. 



