South of France and the Auvei-yne. 3 



occupies the hollow of an ancient crater, proved fertile in a 

 variety of forms. The eddies of the Dor, the mountain torrent 

 which drains the district, and tlie p('r])rii(licular surface of the 

 rock over which the stream is hurried that forms the Grande 

 Cascade, were also productive. 



From the Auveri^ne 1 proceeded to Orleans, and from the 

 source of the Loiret, three miles from that city, collected excel- 

 lent specimens of two rare and interesting forms, namely Ortho- 

 sira arennria, W. Sm., and Gomphonema cristatwn, Ridfs. 



The 4th of July closed my herhorizations, and on that day I 

 plundered one of the fountains of the Champs Elysees in Paris 

 of materials, which added a few names to my roll of French 

 DiatomacccC. 



The gatherings made during the above journey amounted to 

 forty-nine, and the included species may be conveniently divided 

 into five classes. 



1st. Those which were found in the Gulf of Lyons. 

 2nd. Brackish- water forms in localities under the influence of 

 the Mediterranean. 



3rd. S])ccies which were collected in springs and rivers at a 

 low elevation. 



4th. Forms which only occurred at high elevations in the vol- 

 canic districts of the Puy de Dome and Mont Dore. 



5th. Sjiccies or varieties which have not hitherto been figured 

 or described. 



In the following lists I have underlined those species which 

 have not hitherto been found in Britain, and I employ through- 

 out the nomenclature adopted in the " Synopsis,'' whether in the 

 portion already published or in that prepared for the press. 



List 1. Mediterranean forms. 



Epithemia Musculus, Kiitz. 

 Cocconeis Scutellum, Ehr. 



dia]>hana, W. Sm. 



Eupodiscus fiilvas, JV. Sin. 

 Tryblionella Soleajformis, tV. Sm. 

 Surirella fastiiosa, Ehr. 



sti'iatula, Turp. 



Amphiprora alata, Kiitz. 

 Naviciila didyma, Kiitz. 



■ Westii, IV. Sm. 



Pandura, Bre'b. 



Stauroneis pulchella, W. Sm. 

 Plourosigma elongatum, W. Sm. 



angulatum, tV. Sm. 



Synedra affinis, Kiitz. 



fulgens, W. Sm. 



Podosplicnia Ehrenbergii, Kiitz. 



Podosphenia Lyngbyei, Kiitz. 



elegans, W. Sm. 



Rhipidophora elongata, Kufz. 

 Liciuophora splendens, Grev. 

 Fragilaria striatula, Lyng. 

 Striatella unipunctata, Ag. 

 Hyalosira delicatula, Kiitz. 

 Rhabdonema arcuatum, Kiitz. 



Adriaticum, Kiitz. 



Grammatophora marina, Kiitz. 



serpentina, Kiitz. 



Biddulphia pulchella. Gray. 

 Achuanthes longipes, Ag. 



suljsessilis, Kiitz. 



Podosira hormoides, Kiitz. 

 Berkeleyia fragilis, Grev. 



1* 



