The Scottish Naturalist. 37 



chalky-white, encircled with a darker spot, spores rather 

 large, straight, cylindrical, or somewhat fusiform, obtuse 

 at both ends. 



On Glechoma hederacea. July. 

 East. — — — Dee Moray — 



West. — — — — 



Forres. Rev. Dr. Keith. Aberdeen. Prof. J. W. H. Trail. 



Europe. 



(To be continued.) 



LIST OF THE DESMIDS HITHERTO FOUND IN MULL. 



By JOHN ROY. 



The following list has been drawn up from three small samples collected in 

 July, 1878, by Mr. George Ross, Oban, and one collected by Dr. Buchanan 

 White in September, 1881. Mr. Ross collected at Sarsta-beinn, at Loch 

 Snail, and at Tobermory. These localities are indicated in the list by S., 

 L.S., and T. respectively. Dr. White's locality was not specified ; it is 

 indicated by M. 



The list contains 105 species, which a little investigation in other parts of the 

 island would, no doubt, largely increase. With few exceptions, the species 

 here noted are quite common. The rarer species are : Cosmarium intermedium, 

 Delponte, hitherto found in Italy only ; Staurastrum Maamense, Archer, Con- 

 nemara, Deeside, Sweden ; St. Arctiscon, Ehr., a noble species, long known in 

 Connemara, Sweden, North America, and recently found in North Wales ; 

 only one example found in Mr. Ross's Tobermory gathering ; Docidium 

 seeptrum, Kg. ? This is the second time this species, as limited here, has been 

 gathered. It was previously found by Mr. Archer in Connemara, and sent by 

 him to me. In the Mull gathering it was abundant, but not in good condition. 



Hyalotheca dissi liens Sm. — T. ; M. 



Didymopriwn Borreri Ralfs. — M. 



Sphcerozosma excavatum Ralfs. — T. 



Gonatozygon Brebissonii de Bary. — T. 



Micrasterias Jenneri Ralfs. — T. ; M. 



M. denticulata Breb. — L. S. 



M. truncata Corda. — T. ; M. 



M. crenata. — T. 



M. mucronata Dixon. — T. 



Euastrum pectinatum Breb. — M. 



E. oblongum Grev. — M. 



E. crassum Breb. — L.S. ; M. ; T. 



E. ventricosum Lundell. — L.S. ; M. 



E. ampullae eu77i Ralfs. — T. ; M. 



E. Didelta Ralfs.— L.S. ; M. 



E. cuneatum Jenner. — T. 



E. ansatum Ehr. — L. S.; T. ; M. 



