South of France and the Auvergne. 5 



Navicula crassinervia, Br lb. Synedra lunaris, Ehr. 



serians, Kiitz. biceps, W. Sm. 



firma, Kutz. Himantidium Arcus, Ehr. 



> gibberula, Kutz. gracile, Ehr. 



Stauroneis dilatata, W. Sm. pectinale, Kiitz. 



Pinnularia nobilis, Ehr. Fragilaria virescens, Ralfs. 



major, W. Sm. Odontidium hA^emale, Kiitz. 



acuminata, W. Sm. Tabellaria fiocculosa, W. Sm. 



gibba, Ehr. fenestrata, Kiitz. 



divergens, W. Sm. Melosira distans, Kutz. 



late -striata, Greg. nivalis, W. Sm. 



hemiptera, Breb. Ortbosira orichalcea, W. Sm. 



nodosa, W. Sm. Colletonema vulgare, W. Sm. 



tenuis, Greg. 



5. Species or varieties not hitherto figured or described. 



Navicula firma, var. /S, W. Sm. Fragilaria undata, W. Sm. 



Gomphonema capitatura, var, /3, Odontidium auomalum, TV. Sm. 



W. Sm. Achnantbidium lineare, W. Sm. 



capitatum, var. y, W. Sm. coarctatum, Breh. 



Brebissonii, Kutz. Amphitetras antediluviana, var. /3, 



elongatum, W. Sm. W. Sm. 



Diatoraa vulgare, var. jS, W. Sm. Ortbosira spinosa, W. Sm,. 

 grande, W. Sm. 



I subjoin a description of the species and varieties included in 

 the last list. 



Navicula firma, var. ^, W. Sm. Synopsis of Brit. Diato'macese, 

 p. 48. 

 Fresh water. Pic du Capuciii, Mt. Dore ; elevation 4565 feet. 



This is probably the normal Nav. firma, Kiitz. Bacill. xxi. 10^ 

 and I am disposed to refer Nav. amphiffomphus, Kiitz. Bacill. 

 xxviii. 40, to the same species. 



Plate I. fig. 1. Valves of Nav. firma ^. 



Gomphonema capitatum, W. Sm. Syn. Brit. Diat. p. 80. pi. 28. 

 237. 

 Var. 13. Upper portion of frustule almost linear, elongated, 

 equal to, or slightly exceeding the lower. Length of frus- 

 tule -0013" to -0023". v.v. 



Var. y. Much attenuated towards both the extremities. Length 



•0012" to -0016". v.v. 

 Var. y. G. Fusticulus^W . Sm. MSS. Greg, in Mic. Journ. vol. iii. 



p. 39. 



Fresh water. Var. /3. Piiy du Cliergue ; elevation 5576 feet. 

 Ilford near Lewes, Nov. 1853, IF. Sm. River Spey, July 1854, 



