On the CoUojiterous Fauna of the Cape-Verde Islands. 245 



Fig. 10. Evacuated antlierldium of the same species. A special mother 

 cell lias remained beliind in the inner space. 



Fif/. 11, lludimentary antheridiuni oi Asplcniion (ilatiim. Only the lower 

 rino^ cell is cut oil". Its cell-nucleus lay to the left, and was 

 distinct wheu the antheridiuni was generally in focus. 



Ti(/. 12. Like the last. 



Fiij. I'j. Somewhat later developmental state. The upper cell has divided 

 into a shallow bell-shaped outer cell and the central cell : akb 

 as mider lig. 2. 



Fif/. 14. The bell-shaped cell has already been divided into the second 

 ring cell and the opercular cell ; the central cell is still undi- 

 vided. (After treatment with caustic potash and muriatic acid.) 



Fiff. 15. A somewhat older stage. The central cell is already divided 

 into eight cells, of which only four are visible. (Treatment as 

 under fig. 14.) 



Fit/. 10. Mature antheridium ^with three ring cells ; the intermediate 

 ring cell is set obliquely upon the inferior one, so that one side 

 of the latter is excluded from the envelope of the special mother 

 cells. 



Fi(/. 17. Evacuated antheridiuni, with three ring cells, in each of which 

 a spherical nucleus is distinctly visible. 



Fit/. 18. Young antheridiuni of Cihotiitm ScJtidei, seen from above. The 

 central cell is broken up into four quadrants, of which two are 

 already again divided ; the operculum consists of two cells. 

 (After treatmeut with caustic potash and muriatic acid.) 



Fit/. 19. Young antheridiuni, seen from the side. The central cell is still 

 undivided. By a mistake of the lithographer, the circle in 

 which the lower funnel-shaped septum applies itself to the 

 outer wall is placed rather too low down. 



All the figures are drawn with the camera, and magnified 325 diameters. 



XXV. — On Additions to the Coleojyfcrons Fauna of the Cajtje- 

 Verde Islands. By T. Vernon Wollaston, M.A., F.L.S. 



Fam. Hydrophilidae. 



Genus Philiiydrus (Col. Hesp. p. 44). 



J\Iy attention lias lately been drawn by Dr. Sharp (wlio lias 

 studied the PhiJhydri with considerable care) to the fact that 

 Avhat I had hitherto regarded (on the authority, originally, of 

 Aube) as the melanocepkalus of Olivier is not referable, in 

 reality, to that insect. Moreover the Cape-Verde examples 

 a])pear, in addition, to be separable into two species, both of 

 which are distinct from the one (recorded by myself, equally, 

 as the " melanocephalus^''^ which is so universal in the ]\Iadeiran 

 and Canarian archipelagos, and wdiicli Dr. Sharp is of opinion 

 should be identified with the Mediterranean P. politus of 

 Kiister. These two Cape -Verde PJiilhydri he considered to 

 be undescribcd ; and he has lately, therefore, at my own re- 

 quest, published diagnoses of them, which, however, much 

 they may be related inter se, establish at all events the fact of 



