Distribution of the Rhabdophora. 49 



Climacograptus normalis, Lapw. Monograptus Becki, Barr. 



Diplograptus palmeus, Barr. galaensis, Lapw. 



Retiolites Gemitzianus, Barr. Sedgwicki, PoHlock. 



Monograptus priodon, Brown. fimbriatus, Nich. 



exiguus, Nich. turriculatus, Barr. 



Halli, Barr. 



These are possibly the same beds as the strata near Cerrig-y- 

 druidion, in the basin of the Dee, from which Mr. Marr has 

 recently procured Graptolites, as his list of species includes 



Diplograptus palmeus, Barr. Monograptus Sedgwicki, Portl. 



Climacograptus scalaris, His. colonus, Barr. 



Monograptus lobiferus, M l Coy. 



Lake District. — Tn the Lake District the Skellgill or Llan- 

 dovery rocks (Coniston Mudstones) afford Rhabdophora in 

 great abundance. At the typical locality of Skellgill there 

 are two distinct zones of Graptolite-bearing beds. In the 

 lowest {tenuis) zone I have detected 



Diplograptus folium, Sis. Monograptus argutus, Lapw. 



sinuatus, Nich. spiralis, Geinitz. 



confer tus, Nich. Sedgwicki, Portl. 



tamariscus, Nich. tenuis, Portl. 



Climacograptus normalis, Lapw. cyplius, Lapw. 



Retiolites perlatus, Nich. timbriatus, Nich. 



Monograptus gregarius, Lapw. Rastrites peregrinus, Barr. 



The higher (or argenteus) zone has afforded me 



Diplograptus Hughesi, Nich. Monograptus Hisingeri, Carr. 



sinuatus, Nich. lobiferus, M'Coy. 



tamariscus, Nich. attenuatus, Hopk. 



Climacograptus normalis, Lapw. gregarius, Lapw. 



Diplograptus folium, His. argutus, Lapw. 



Rastrites peregrinus, Barr. leptotbeca, Lapw. 



Monograptus argenteus, Nich. timbriatus, Nich. 



From beds at Knock near Dufton, higher than the typical 

 argenteus zone, Monograptus exiguus, Nich., and Rastrites 

 distans, Lapw., were collected by Prof. Nicholson and myself 

 in 1874. From a thin black seam in the Pale Shales above 

 we procured a Monograptus allied to M. Halli, Barr. 



In addition to many of the foregoing, Prof. Nicholson* 

 quotes from the Coniston Mudstones the following forms : — 



Diplograptus vesiculosus, Nich. Diplograptus putillus, Hall. 

 pristis, His. angustifolius, Hall. 



The first named probably occurs in the lowest zone ; the 

 rest may be new species. 



Scotland. — The south of Scotland contains the most prolific 

 Graptolite-bearing beds of Llandovery age yet discovered in 

 Britain. These are the well-known Birkhill shales of the 



* Nicholson, Quart. Journ. Geol. Soc. 1868, p. 523. 

 Ann. & Mag. N. Hist. Ser. 5. Vol. v. 4 



