JONES CAMBRIAN ENTOMOSTRACA. 185 



Fig. 7. Agnostus EsJcriggei, Hicks. Enlarged. Porth-y-rhaw, St. David's. 



8. scarabceoides, Salter. Enlarged. Ditto. 



9-14. scutalis, Salter. Enlarged. Ditto. 



15. Entomis bujjrestis, Salter, sp. Enlarged. Ditto. 



16. Leperditia Hicksii, Jones. Enlarged. Ditto. (Drawing reversed and 



imperfect.) 



17 & 18. Enlarged. This peculiar and rather doubtful fossil is not at all 

 uncommon in the middle beds of the Menevian Group, and is fre- 

 quently surrounded by a black carbonaceous-looking substance. 

 Occasionally it is found in the interior of a email black nodule. 

 Tliis would tend to bear out the view that it belongs to the embryonic 

 stage of some of the larger Trilobites. 



19. Protocystites 7nenevensis, Hicks. Enlarged. From Porth-y-rhaw, St, 

 David's. 



20-23. Arionellus longicephalus, Hicks. Ditto. 



24-26. , Hicks. From near Maentwrog, North Wales (cabinet 



of D. Homfray, Esq., Portmadoe). 



Plate VI. 



Figs. 1-4. Erinnys venulosa, Salter. From Porth-y rhaw, St. David's. Fig. 1 

 is enlarged to show the ornamentation on the cheeks. 



5 & 6. , Salter. From the Waterfall Valley, Maentwrog (cabi- 

 net of D. Homfray, Esq., and Cambridge Museum). 



7. Carausia me^ievensis, Hicks. Enlarged. From middle beds of the 

 Menevian Group, at Porth-y-rhaw, St. David's. 



8 & 9. Holoccphalina inflata. Hicks. Enlarged. The head showing the 

 strong nuchal spine, which, though not restricted to this genus, is 

 yet a characteristic feature. 



10. ■, Hicks. A group, of the natural size. From a creek west 



of Porth-y-rhaw, St. David's. 



11. Conocoryphe coronata,'B&vva,ndQ. Natural size. From the Waterfall 



Valley, Maentwrog, North Wales (cabinet of D. Homfray, Esq.). 



12. Homfrayi, Salter. Ditto. Ditto. 



Plate VII. 



Figs. 1-7. Anopolenus impar, Hicks. From Porth-y-rhaw, St. David's, and 

 Waterfall Valley, Maentwrog (Cambridge Museum, and cabinet of 

 Mr. Hicks). 



8-11, Salteri, Hicks, From Porth-y-rhaw, St. David's. Fig. 10 is 



one of the free cheeks, with a portion of the eye-lobe attached. Out 

 of many scores of specimens discovered, in no case have the free 

 cheeks been seen fixed properly to the head ; but the sutures are well 

 marked generally, and are sufRciently distinct to indicate the true 

 position and mode of attachment of the loose cheeks, which are 

 found in the same beds with the other fragments. 



12 & 13. Stenotheca cornucopia, Salter. Enlarged. From Porth-y-rhaw, 

 St. David's. 



14. Cyrtotheca hamula. Hicks. Ditto. Ditto. 



15 & 16. Theca penultima, Ricks. Natural size. Ditto. 



17. corrugata, Salter. Ditto. Ditto. 



18 & 19. stiletto, Hicks, Ditto. Ditto. With the operculum mag- 

 nified. 



