142 



will Find an atlcmpt at a naturai classification oi Ihe Licmophorac 

 intcnded to replacc the artitìcial system cstablished by Grunovv. 



1 take this opportunity to ask persons who are in possession of 

 material containing Licmophora or Climacosphenia to assist me in 

 my Monography by sending slides or better even raw material, the 

 latter, as far as possible, not dried up. I shall be glad to give in ex- 

 change slides or material from the Mediterranean, the Black sea, 

 the sea of Azof, the Caspian sea, the Pacific ocean (California, re- 

 cent as well as tossii), the Philippine Islands etc. Material containing 

 Licmophorae from the tropical and the arctic regions would bc the 

 most desirable, although especially favourable one from the North 

 See and the Mediterranean (in fact from any locality) will be also 

 wellcomed. 



I bave found and studied most of the known species, stili thcre 

 are some which I did not happen to mcet with or which I would 

 likc to bave from some new locality, as for instancc: L. anglica (Kz.) 

 Grun., L. li\alina (Kz.) Grun., L. borealis Kùtz., L. coniiniinis (Heib.?) 

 Grun., L. crislallìna (Kz.) Grun., L. Aiistralis (Kz.) Grun., L, longis- 

 sima Leud. Fortm., L. nubeciihi (Kz.) Grun., L. tincta (Ag.) Grun., 

 L. Jurgensii var. finmarchica Grun. and var. cJiersonensis Grun., L. 

 Katìitschalìca Grun. and the different varieties of L. Lyngbyei. 



If any one possesses slides containing these (or any other) spe- 

 cies 1 would kindly ask them to cxchange their slides for other ones, 

 or to lend me them for a short timc : I engagé to return them in a 

 safc condition. 



Material as well as slides should be sent to M.' Ed. Thum, 3, 

 Johannisallce, Leipzig, Germany, who will forward them to me. 



I. L. adriatica Mer, [fig. i]. 



Valve broad, davate, inllated at the upper third, abruptly atte- 

 nuatod in its middle part, with strongly concave margins, upper end 

 slightly attenuated, with apex rounded or truncate, lower part nar- 

 row^ inferior apex usually not inflated. Pseudoraphe indefinite, striae 

 fine. Girdle face cuneate, modcratly broad, walls of the frustule so- 

 mcwhat Ihick, upper angles rather acute. Septa superficial, strong, 



