ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 573 



Worm-fauna of Madeira.* — P. Langerhans has published the 

 fourth of his contributions on the worm-fauna of Madeira, in the 

 course of which he describes various new species and one new genus. 

 Among other points of interest the author has some suggestions as 

 to the divisions of the Serpulidfe, our knowledge of which is in a most 

 unsatisfactory condition. In that family he recognizes three types ; 

 the first of these is Serjudci itself, in which the thoracic segments 

 bear only one kind of dorsal seta ; here belong Serpida, Eupomatm, 

 Pomatocerus, and Placostegiis. Filograna is the second type, and in 

 it all the thoracic segments behind the second have, in addition to 

 the Serpulid setae, those of the kind first detected by Claparede in 

 Salmacina. Here we have Spirorbis and others. The third type is 

 represented by Vermilia hifundibulum, in which a fresh type of seta, 

 in addition to those already noted, is present. 



Of the twenty species of Nemerteans found by Langerhans, seven- 

 teen are known to be members of the European seas. 



New Species of Rotifer. t — Sara G. Foulke describes a new species 

 of rotifer under the name Apsilus hipera. In common with all 

 members of the genus, they possess, instead of rotatory organs, a 

 membranous cup or net, which is used for the capture of food. The 

 specific distinction of the new form consists chiefly in the structure 

 of the net, the presence of a true stomach in addition to the usual 

 crop, and the presence of cilia inside the net. It is proposed to unite 

 the forms Apsilus lentiformis Mecznichoff, Dictyopliora vorax Leidy, 

 and Cupelopagus hucinedax, Forbes, and the new species in one genus, 

 ApsUus (Fam. Apsilidse), in consequence of their strong points of 

 resemblance. These are, briefly, the presence of two eye-spots, of a 

 membranous cuj), of a mastax exactly similar in all, of the absence 

 of tail or foot-stalk, of the absence of carapace, and of the similar 

 habits. 



Prof. Leidy subsequently declared all four forms to form the same 

 species, with which opinion Miss Foulke does not agree. 



Echinodermata. 



Development of the Germinal Layers of EcMnoderms.J — E. 



Sclcnka finds that egg-cleavage in Echinoderms is regular, but that 

 of (Jphiurids and Asterids is really " pscudoregular," and that of 

 Echinids regular with polar difiercntiation ; we cannot as yet exactly 

 define what wc mean by a regular cleavage, and its various modifica- 

 tions arc as yet insufficiently known ; we may, however, distinguish 

 under its head those eggs into which the first two blastomeres arc of 

 the same size, and those in which cleavage is on tlio whole regular, 

 with the exception of the first plane of cleavage. The various modes 

 of cleavage exhibited by the eggs of Echinoderms arc of no value for 

 the phylogenetic history of the grouj) ; the influence of cenogeuy is 



♦ Zeitwcbr. f. Wiaw. Zool., xl. (1884) pp. 217-8.5 (3 pis.), 

 t Pror. Acad. Nat. Hci. rhihid., 1884, pp. 37-41 (1 pi.). 

 i 'Studicn iibtr EutwickclungBgcschichtc,' ii., Wicsbadeu, 1883, pp. 28-CI 

 (6 plB.). 



