1 A7 

 1903.] FROM ZASZIBAK AND BMIISH EAST AFRICA. 



been .tudiert only in a, tew cases. Consequently it cannot 

 Srt^ltdy, be^mployed .« one of the pnncipal character. 



'"r;ivfwJl'':?S;;:tivc taWe »£ the species of the genus 

 hitherto described, with their distribution :— 



A. Species with eyes on the anterior part of the margin only. 

 a. Ovaries dorsal. 



., ,«,.,„ (CStte) [1] [^^SjrSnH^r 



/3. Ovaries ventral. ^ 



Marginal eyes extremely small. 

 S. neapolitanus (Delle Chiaje) [1]. Mediterranean. 



Marginal eyes moderate, brain-eyes absent ? 

 S. zanzlbaricus, sp. nov." Zanzibar. 



y Position of ovaries doubtful. 

 ,S'./ror.i«Z.-.Yerrill[2]. New England. 



S.limosus J)iesi..g[l]. ^-V2 



S. conglomercttus Diesmg [IJ. Japan. 



B. Species with eyes completely surrounding the margin. 

 a. Ovaries dorsal. 



Small brightly coloured species. 



^ , • •• T „ ni ' Mediterranean. 



,S^. plessisii Lang [IJ. 



h Ovaries ventral. 

 S.suesensism.venh.n\\. Zanzibar. 



c. Position of ovaries doubtful. 

 S. «««Mfe Ehrenb. [1] BWlf Sea 



S. yus Czerniowsky [1]. ^:*| ^tad. 



,S'. Uebra Yerrill [2 J. ^^"^ » 



Since the publication of Lang's Monograph, the following 

 species have been removed from the genus :— 



1 Stylochus littoralis {Yevvi\\) = Planocera elliptica Gnard. 

 This species is now referred by Yerrill to a new genus, Eustylo- 

 cJrchracterised by the presence of a median female anterior 

 atessorrvesicle,appa^-entlys^^^^^^^^ 



2. Stylochus^ sargassicola (Mertens) is referred by von Graff 

 to the genus Stylochox)lana [3]. 



Verrill's species Stylochus crasms [2] is, I think, evidently not 

 a member of this genus. 



Family LEPTOPLANiDiE. 

 Phylloplaxa lactea, gen. et sp. nov. (Plate IX. fig. 3.) 

 ^hore form " White, with minute grey dots scattered sparsely 

 over dorsal surface." Collected 19.2.01 ; several specimens. 



