PLATE XIY. 



FIGS. PAGE 



Angelina sedgwicki, Salter. 112 



1. Head, showing duplication of the sutures. Upper Tremadoc, near Tre- 



madoc. Museum of Practical Geology, 10191. Nat. size. 



Dikelocephalus discoidalis, Salter. 115 



2. Glabella and frontal limb. Upper Lingula Flags, Ogof-ddu, Criccieth. 



Museum of Practical Geology, 10214. (Figured by Salter, Mem. 

 Geol. Surv., vol. iii, pi. v, fig. 18.) x 1-|. 



3. Glabella and eye. Upper Lingula Flags, Ogof-ddu, Criccieth. Museum 



of Practical Geology, ld209. x H. 



4. Glabella and fixed cheek. Upper Lingula Flags, Ogof-ddu, Criccieth. 



Museum of Practical Geology, 10210. x ]|, 



5. Free cheek and part of frontal limb. Upper Lingula Flags, Ogof-ddu, 



Criccieth. Museum of Practical Geology, 10213. (Figured by 

 Salter, Mem. Geol. Surv., vol. iii, pi. v, fig. 18a.) x 1^. 



6. Free cheek. Upper Lingula Flags, Carreg-wen, Borth. Sedgwick 



Museum. x 1-|. 



7. Free cheek. Upper Lingula Flags, Carreg-wen, Borth. Sedgwick 



Museum. x 1-1. 



Dikelocephalus celticus, Salter. 116 



8. Interior of tail. Upper Lingula Flags, Ogof-ddu, Criccieth. Museum 



of Practical Geology, 10208. (Probably used by Salter in Mem. 

 Geol. Surv., vol. iii, pi. v, fig. 21.) Nat. size. 



9. Tail, internal cast. Upper Lingula Flags, Ogof-ddu, Criccieth. Museum 



of Practical Geology, 10206a; completed from its counterpart. 

 10206. (Probably used by Salter in Mem. Geol. Surv., vol. iii, 

 pi. v, fig. 22.) x li 



10. Tail, with part of test preserved. Upper Lingula Flags, Ogof-ddu, 



Criccieth. Museum of Practical Geology, 10211. (Figured by Salter 

 as Dikelocephalus ? sp., Mem. Geol. Surv., vol. iii, pi. v, tio-. 2<>.) 

 x 11 



Dikelocephalina furca (Salter). 118 



11. Head and part of thorax. Upper Tremadoc, Garth Hill, Portmadoc. 



Mr. G. J. Williams' Collection. Nat. size. 



12. Interior of tail. Bottom beds of the Upper Tremadoc, Moel-y-Gest, 



Portmadoc. Sedgwick Museum. Presented by Mr. Ash (a 30 of 

 Salter's Catalogue). (Probably the original, or its counterpart, 

 of Mem. Geol. Surv., vol. iii, pi. viii, fig. 10.) Nat. size. 



13. Interior of tail and last thoracic segment. Upper Tremadoc, Garth, 



Portmadoc. Sedgwick Museum. Presented by Mr. D. Homfray 



(a 3D* of Salter's Catalogue), x 1|. 



Apatokephalus serratus (Boeck). 122 



14. Cranidium. Upper Tremadoc, Amnodd Wen, Arenig. Mr. G. .1. \\ llliams' 



Collection. x 5. 



