ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 243 



Lieberkiilin's name Eph. Miilleri for his own var, asfrodiscus. The 

 Bohemian Eph. fluviatilis is identical with the British Spongilla 

 fluviatilis. Turning to the different layers of the wall of the gem- 

 mules, he finds the new species to be distinguished by possessing two 

 concentric layers of birotulate spicules; of these the outer layer 

 project from the external parenchymatous layer by their shafts and 

 outer disks, the inner disks lying in the subjacent parenchyma; a 

 thick parenchymatous layer is now found (as we pass inwards), con- 

 taining on its inner aspect the internal layer of birotulate spicules, whose 

 inner disks are in apposition with the brown chitinous membrane, 

 which immediately incloses the germinal corpuscles. Trochospongilla 

 erinaceus, from the Elbe, shows the following characters in its gem- 

 mules. The layer which represents the parenchymatous layer of 

 other Spongillidce is modified to form a mass of five- to six-sided long 

 prismatic columns, whose long axes are perpendicular to the surface of 

 the gemmule ; they are divided transversely into air chambers ; the 

 walls are firm and glistening, and probably consist of chitin. Beneath 

 this layer come the amphidisks, lying on the very stout and laminate 

 chitinous membrane. The parenchymatous layer, as here modified, 

 probably acts as an aerostatic apparatus for the transportation of the 

 gemmule, and corresponds exactly to the natatory rings of the stato- 

 blasts of many fresh- water Polyzoa. Dr. Vejdovsky has hitherto been 

 unable to discover a similar arrangement in the nearly allied North 

 American Meyenia Leidii. 



New Genus of Sponges.* — G. C. J. Vosmaer gives an account of 

 Velinea gracilis, a new genus or species of sponge found in the Bay 

 of Naples. A study of this form has convinced him that the water 

 which enters a sponge, having once passed a ciliated chamber, does not 

 enter another, but is carried away. The skeleton is very remarkable ; 

 it consists of a rather regular network of horny fibres, lying in three 

 planes, and the six fibres forming the longitudinal, concentric, and 

 radial systems meet at approximately right angles, so that the con- 

 tained meshes are nearly square. The skeleton is, speaking generally, 

 solid and hexactinellid. 



The author does not feel himself able to speak definitely as to the 

 characters of the epithelial cells, as he was not successful in detecting 

 their limits; a similar kind of epithelial cell is found in all the 

 afferent and efferent canals. The collar-cells are remarkable for their 

 small size. 



In discussing the systematic position of Velinea, the author enters 

 in detail into the characters of the allied families Aplysinidse, Aply- 

 sillidaB, Spongidse, and HircinidsB ; placing it in the family of the 

 Spongelida3. Useful differential characters are given for these five 

 families. 



Protozoa. 

 Biitschli's 'Protozoa.' — Parts 20-25 of this work have been pub- 

 lished with plates xxxix.-l. They deal with the Mastigophora, Diesing's 

 name being applied to what are now more often called the Flagellata. 



* MT. Zool. Stat. Neapel, iv. (1883) 437-47 (2 pis.). 



