ZOOLOGY AND BOTANY, MICROSCOPY, ETC, 859 



great uncertainty to overhang the real cliaraeters of tlie older 

 species. 



In his special description of those species found in Bohemia he 

 recognizes but one genus, Spongilla, but divides it into three sub- 

 genera, Euspongilla (Spongilla s. str. of Carter), characterized as pos- 

 sessing smooth skeleton-spicules and small spined parenchyme- 

 spicules ; gemmules either naked or invested in a parenchymatous 

 coat, containing spined spicules ; Epliydatia (Gray's genus, restricted 

 to species with toothed rotulee to the amphidiscs, and hence corre- 

 sponding only to part of Meyenia Carter) ; Trochospongilla, for species 

 of Meyenia Carter, with the margins of the amphidisc rotulse entire. 

 Dr. Vejdovsky gives lists of synonyms of the above species, which he 

 describes, separating them in some cases into distinct varieties. As 

 the main subject has been so lately dealt with by Carter and 

 Dybowski,* it will be sufficient to indicate the chief novel facts and 

 views introduced here, with notes on some species scarcely known to 

 English students. 



Euspongilla lacustris, includes *S^. jordanensis of Kusta, which 

 Yejdovsky has examined afresh. 



Two forms are distinguished by the structure of the gemmules, 

 viz. var. macrotheca, the gemmule of which has a weak parenchyme- 

 layer, devoid of a chitinous membrane, and is greenish in colour, and 

 lacustris s. str., with brown gemmules, with a thin chitinous membrane 

 to the parenchyme-layer in addition to the thick inner chitinous 

 layer. 



Euspongilla jordanensis Vejdovsky, nee Kusta. This species has 

 been only hitherto described with certainty in the Bohemian language ; 

 the present full description and figures show that it is distinguished 

 from S. sihirica Dybowski only by the superior thickness of the 

 parenchyme-layer of the gemmule, and by the smoothness of the 

 parenchyme-spicules. 



A var. druliceformis is established for a specimen recalling the 

 genus Druilia Gray (Parmula Carter), by having the gemmule 

 covered with shield-like structures ; these, however, appear to require 

 re-examination. 



Epliydatia fluviatilis is identified with Meyenia No. 1 of 

 Dybowski. 



Epliydatia mulleri Lieberkiilin, includes Epliydatia No. 2 and 

 Meyenia No. 2 of Dybowski; Vejdovsky distinguishes a forma A, 

 with thick shafts and irregularly toothed rotules to the amphidiscs 

 from forma B, in which the shafts are slender and the rotulae regularly 

 stellate ; as " var. ? astrodiscus" Meyenia No. 3 of Dybowski is also 

 placed under E. mulleri. 



Trochospongilla erinaceus Ehrenberg. The surface is marked with 

 curious stellate grooves. The ends of the skeleton-spicules are 

 smooth, while all the rest of their surface is covered with large sharp 

 spines. The rotulaB of the amphidiscs have the edges entire and 

 usually turned up, saucer-wise. 



The paper concludes with a table of the distinguishing characters 



* See this Journal, ante, p. 378. 



3 M 2 



