266 



DESMIDIE^ OF SUTTON PARK. 



(2)GoBm&ri\impseudo-pyramidatum 



,, Ralfsii. 



,, tinctum. 



,, undulatum. 



Xantnidium armatum. 



,, cristatum. 



Arthrodesmus convergens. 



,, Incus. 



Staurastrum asperum. 



,, dejectum. 



,, dilatatum. 



„ hirsutum. 



„ margaritaceum. 



,, muricatum. 



„ muticum. 



Staurastrum orbiculare. 



„ polymorphum. 



,, punctulatum. 



,, sexcostatum. 



„ spinosum. 



,, spongiosum. 



Tetmemorus Brebissonii. 



,, granulatus. 



,, laevis. 



Penium Brebissonii. 



,, closterioides. 



,, Cylindrus. 



,, Digitus. 



„ interruptum. 



„ Jenneri. 



,, margaritaceum. 

 (3) ,, Ndgelii. 



September, 1880. 



(4) Penium Navicula. 

 Docidium clavatum. 



,, Ehrenbergii. 

 ,, nodulosum. 

 ,, truncatum. 

 „ ,, var. 



Closterium acerosum. 

 ,, acutum. 



,, attenuatum. 



,, Cornu. 



„ costatum. 



„ Dianas. 



„ didymotocum. 



„ „ var. 



[Baileyanum. 



(5) ,, directum. 



,, intermedium. 



,, juncidum. 



„ Leibleinii. 



,, lineatum. 



„ Lunula. 



(6) ,, Pritciiardianum. 

 ,, rostratum. 



,, setaceum. 



„ striolatum. 



Spirotaenia condensata. 



„ obscura. 



Pediastrum Boryanum. 



,, Tetras. 



Scenedesmus obliquus. 



,, obtusus. 



„ quadricauda. 



A. W. Wills. 



OEIGIN OF THE EOCKS AND SCENERY OF 

 NORTH WALES. 



BY J. J. HARRIS TEALL, M.A., F.G.B., ETC., LATE FELLOW OF 



ST. John's college, Cambridge. 



(Continued from page 241.) 

 We turn now to the second portion of our subject, the origin of the 

 existing scenery. That the hills and the valleys are not directly due to 

 the disturbances which have affected the district is proved beyond the 

 shadow of a doubt by a glance at any accurate geological section. 

 Snowdon, for instance, lies in a synclinal, so that if no material had 

 been removed the land surface to the N.W. and S.E. would be 



(2.)— Cosmarium pseulo-pyramidatum. Lundell, Desm. Suec, 1871. Archer, 



Journ. Bot., 1874, (Ireland.) 



(3.)-Penium Nagelii. Bi6b. in Prit. Infas., 1861. Nag, Ein. Alg., 1819, (Ireland.) 

 (4.)— Penium Navicula. Br6b. Liste Desm., 1656, (Ireland.) Archer, Nat. His. 



Rev., 1858, (Ireland.) 



(5.)— Closterium directum. Archer, Mic. Journ., 1862, (Ireland.) 



(6.)— Closterium Pritchardianum. Archer, Mio. Journ., 1862, (Ireland.) 



