Mr. T. V. Wollaston on Madeiran Coleoptera. 99 



does not appertain to the intine as a thickened lamina, as 

 Schacht implies, but from the first lies free between the two 

 coats of the pollen, and at a later period becomes strongly 

 attached to the extine. Consequently it clings to the extine 

 when this is torn from the intine and gets so inverted that 

 its setaceous outer surface is turned inwards. 



The pollen- cells of Thunbergia, with their thickened extine 

 disposed in spiral lines, remind us at once of the spiral-fibres of 

 the vessels of Cryptogamia, and represent a modification of the 

 spores of Equisetse ; whilst the pollen of Ipomcea, with its seta- 

 ceous integument, may be considered like ligneous Vaucheria 

 zoospores, as is proved by my history of the development of the 

 latter (Botan. Zeitung, 1852, p. 95, pi. 2. fig. 12 a). 



Each cilium of the vibratile epithelium of the zoospores of 

 Vaucheria, and likewise the cilia of the cells of antherozoids and 

 spiral fibres, are vesicles, which in the course of development as- 

 sume a hair-like form, and it is most probable move the body to 

 which they are attached, both by the agency of a great faculty of 

 imbibition in their unequally thickened walls, and by great 

 efforts in the diffusion of their contents with water — actions 

 which proceed for some time with oscillating movements before 

 an equilibrium is attained. 



It can only be want of knowledge of the developmental 

 history of these cells that can suggest the opinion that cilia are 

 direct outgrowths of the primordial vesicle. 



[To be continued.] 



X. — On Additions to the Madeiran Coleoptera. 

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



Fam. Dytiscidse. 



Genus Eunectes. 



Erichson, Gen. Dytic. 23 (1832). 



Eunectes subcoriaceus, n. sp. 



E. oblongo-ovatus, subdiaphano-coriaceus, pallide diluto-testaceus, 

 clypeo antice leviter emarginato ; capite postice nigro et macula 

 frontali magna distincta antice profunde bipartita ornato ; pro- 

 thorace vitta transversa parva fracta nebuloso, ad latera oblique 

 subrecto, angulis posticis acutiusculis, subaequali, margine postico 

 infra angulos leviter elevato ; scutello subsemicirculari ; elytris 

 punctis niagnis triplici serie et punctulis minoribus parvis (anterius 

 minutis levioribus et magis remotis) nigris notatis, utroque macula 



7* 



