part 4] UPPElt OltDOVKTAX OF TILE BEUWYX HILLS. o07 



Davidson l from Klios-Fawr Llanfyllin is almost certainly from 

 the Ashgillian (Calyvieiie-quadrata Beds) and not from the 

 Lower Llandovery as stated ; similarly, his specimens from 

 Lledfron Llanfyllin- are also Ashgillian {PlulUpsinclla Beds) 

 and not Caradocian. 



OltTHIS (DaLMAKELLa) sp. ci. 



This form is, probably, included in some of the fossil lists as 

 Ortliis crispa vars. ; hut it lacks ornamentation on the rihs, and 

 only has it in the grooves. Here, however, the ornamentation does 

 not consist of simple laminae, hut of a series of honeycomh-like pits 

 arranged in longitudinal groups. The ribs bifurcate generally 

 once, at about half their length. 



The shells are generally fragmentary, and no internal structures 

 have been obtained ; but the ornamentation is easily distinguished, 

 and the form appears to be characteristic of the higher 

 Pliillipainella Beds and the lower part of the Galjjmene- 

 (j it ail rata Beds. 



In conclusion, I have to express inv thanks to Prof. J. E. Man 1 

 and to Miss Gr. L. Elles for much help and useful criticism ; also 

 to Prof. 0. T. Jones for examining and naming some of the 



brachiopods. 



EXPLANATION OF PLATE XXVI. 



Trilobites from the Ashgillian (Calymene-quadrata Beds) of the Blaen-y-cwm 

 valley, 5 miles west-north-west of Llanfyllin (Montgomeryshire). 



[The locality-letters are shown in the map, fig. 3, p. 496.] 



Fig. 1. CaJymene quadrata sp. nov. Holotype from AS on the crags of 

 Craig Fawr, Blaen-y-cwm valley, Llanfyllin. Specimen No. 31742- 

 43. Museum of Practical Geology, Jermyn Street. X 2"5. 



2. Do. A more perfect head, without free cheeks ; tJ 3, same locality. 



Sedgwick Museum, Cambridge. X 2 - 5. 



3. Lichas geilcel Nicholson & Etheridge, var. Pygidium from ('A, same 



locality. Sedgwick Museum, Cambridge. X 6. 

 Figs. 4 & 5. Phacopn (PtenjgoHietopusjTiruiigniaiii Portlock, var. Two views 

 of an enrolled specimen from S3, same locality. Sedgwick 

 Museum, Cambridge. X 2 - 5. 



1 " Monograph of the British Fossil Brachiopoda ' vol. iii, Pal. Soc. 1864-71, 

 pi. xlvii, fig. 18. 



2 Ibid. pi. xlvii. figs. 8-15. 



[For the Discussion, see p. 541.] 



