670 J.HOPKINSON AND C. LAPWORTH ON THE GRAPIOLITES OF 



5 a-5 d. Didymograptus Nicholsoni, Lapw. 5 a, nat. size ; 5 b, 5 c, 5d, por- 



tions of the same, inagn. 5. From Llanvirn Quarry : Upper Arenig 

 (coll. J. K). 



6 a-Q c. Didymograptus affinis, Nick. 6 a, nat. size ; 6 b, part of a branch 



nat. size ; 6 c, a portion of the same, magn. 5. From Porth-hayog, 

 Ramsey Island : Upper Arenig {coll. H. H.). 



7 a-7 c. Didymograptus indentus, |Hail, sp. 7 a, nat. size ; 7 b, part of the 



same, magn. 5 ; 7 c, the distal end of a branch, mag. 5. From Porth- 

 hayog : Upper Arenig (coll. H. H.). 7d. var. nanus, Lapw., nat. size. 

 From Llanvirn Quarry : Upper Arenig. 



8 a-8 e. Didymograptus bifidus, Hall, sp. 8 a, nat. size ; 8 b, part of the 



same, magn. 3 ; 8 c, nat. size ; 8 d, 8 e, young individuals, magn. 5. 

 From Porth Hayog: Upper Arenig (coll. H. H.). From Llanvirn 

 Quarry : Upper Arenig (coll. J. H.). 



9 a & 9 b. Tetragraptus quadribrachiatus, Hall, sp. 9 a, a branch, nat. size ; 



9 b, part of the same, magn. 5. From Whitesand Bay (near the slate- 

 quarry) : Middle Arenig (coll. J. H). 

 10. Tetragraptus serra, Brongn. sp., nat. size. From Whitesand Bay : 

 Middle Arenig (coll. J. H.) 



11 a & 11 b. Tetragraptus Halli, Hopk., nat. size. From Whitesand Bay : 



Middle Arenig (coll. J. H.). 



12 a-12d. Tetragraptus Hicksii, Hopk. 12 a, 1 2b, nat. size ; 12 c, a, branch, 



nat. size; 12 d, part of the same, magn. 5. From Whitesand Bay : 

 Middle Arenig (coll. H. H. and J. H.). 



Plate XXXIV. 



Illustrative of the Arenig Bhabdophora described by Mr. Lapworth (with th 

 exception of Clematograptus implicatus and Phyllograptus stella, described 

 by Mr. HopJcinsori). 



Fig. 1. Clematograptus implicatus, Hopk., natural size. From Whitesand Bay : 

 Middle Arenig (coll. J. H.). 



2 a & 2 b. Nemagraptus capillaris, Emm. 2 a, nat. size ; 2 b, magnified 



4r| diameters. From Llanvirn Quarry : Upper Arenig (coll. H. H.). 



3 a and 3 b. Dicellograptus moffatensis, Carr., sp. 3a, nat/size. 3 b. magn. 



4^ diam. From Llanvirn Quarry: Upper Arenig (coll. J. H.). 



4 a-4/. Climacograptus confertus, Lapw. 4 a, 4 c, and 4 e, nat. size ; 4 b, 



4 d, and 4/. magn. 4£. From Porth Hayog, Bamsey Island : Upper 

 Arenig (coll. D. H. $ H. H.). 



5 a and 5 b. Diplograptus dentatus, Brongn. sp From Llanvirn Quarry . 



Upper Arenig (col. H. H.). 5 c-5 k, specimens illustrating the various 

 appearances presented by the compressed polypary in this species. 

 5a, 5c, 5e,5g. and5e, nat. size; 5b, 5d, 5f 5h, and 5k, magn. 4^. 

 Llanvirn Quarry : Upper Arenig (coll. J. H.). 

 6. Phyllograptus stella, Hopk., nat. size. From Road Uchaf, Bamsey Island : 

 Lower Arenig (coll. J. H.). 



7 a-7 c. Glossograptus ciliatus, Emm. 7 a, nat. size ; 7 b, magn. 4| ; 7 c, 



proximal end, magn. 4£. From Llanvirn Quarry : Upper Arenig 

 (coll. H.H.). 



8 a-8 c. Trigonograptus ensiformis, Hall, sp., nat. size. From Boad Uchaf, 



Bamsey Island : Lower Arenig (coll. J. H.). 



9 a-9 d. Trigonograptus truncatus, Lapw., nat. size. From Boad Uchaf : 



Lower Arenig (coll. J. H.). 



Plate XXXV. 



Illustrative of the Llandeilo Bhabdophora described by Mr. Lapworth. 



Figs. 1 a-1 c. Didymograptus etiodus, Lapw. 1 a, nat. size ; 1 b, portion of the 

 same, magn. 4%;lc. a large branch, nat. size. From AbereiddyBay : 

 Lower Llandeilo (coll. H. H.) 

 2a-2f. Didymograptus Murchisoni, Beck, sp. A selection of examples 

 illustrating the more typical forms of this protean species. From 

 Abereiddy Bay: Lower Llandeilo (coll. H. H. Sf J. H.). 



