SALTER AND HICKS MENEVIAN EOSSILS. 53 



fulcrum, which is placed rather far from the axis ; the spines com- 

 prise rather more than a third of the whole length of the pleurae, 

 and are rather dilated at the base. Our figure does not show these 

 spines ; but better specimens have lately been discovered. Tail 

 unknown. This species is easily distinguished from any of the 

 others found in the '' Menevian Group " by its large size, wide 

 anterior margin, the small, highly convex, and deeply furrowed 

 glabella, and wide cheeks. Its nearest ally is a new species {G. 

 perdita, PI. II. fig. 3), found by me at the end of last summer, 

 about 200 feet lower down in the Cambrian series (purple and 

 grey beds) ; but as the last-named species is smaller, and has a far 

 less strongly developed anterior margin, as well as a wider glabella, 

 it is not likely to be mistaken for it, especially when we recollect 

 that the one occurs in the purple Cambrian beds and the other in the 

 " Menevian Grouj)," and that as a rule the range of the species in 

 these lower series extends through but a slight thickness of the 

 strata. — H. H. 



Locality — Grey beds at the base of the " Menevian Group." 

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



2. CoNOcoEYPHE APPLANATA, PI. II. figs. 1, 2, 4, and 5 (juv.). Salter, 

 Brit. Assoc. Report, 1865, p. 285. 



Length from J to 1 inch, breadth about | inch. Porm broad- 

 ovate, depressed. Head semicircular, rather wider than the body, 

 surface very slightly tubercular, marginate all round, and angles 

 produced into short strong spines. Glabella parabolic, more or less 

 convex, and indented by three lateral furrows, which, however, are 

 rather indistinct in the most convex specimens ; the cheeks are broad 

 and compressed, and bear small but prominent eyes rather remote 

 from the glabella, being distant from it by a space about equal to its 

 width, and connected with it by strongly marked ocular ridges; the 

 facial sutures run forwards and rather outwards above the eyes, and 

 backwards and outwards below, cutting across the hinder margin near 

 the outer angles. Thorax of 14 rings, axis slightly convex, and taper- 

 ing towards the tail ; pleurae long and narrow, twice as long as the 

 rings of the axis, deeply sulcate, and bent slightly backwards at 

 the fulcrum, which is placed about midway. Tail semicircular, with 

 a tapering, pretty strongly marked axis of three segments ; limb 

 marked by three ribs, marginate. This species is distinguishable 

 from C. varioJaris by many of the characters above given, but esj)e- 

 cially by the want of the very strong tuberculation and the strongly 

 raised margin of the latter species — and also by the presence of a 

 well-defined ocular ridge, which, if present, is scarcely at all visible 

 in G. variolaris. C. applanata has no tubercle on either the axial 

 rings or pleurae, and is altogether a much smaller species than C. 

 variolaris. — H. H. 



"We have been fortunate in finding the very young of this species ; 

 it is a capital example of the metamorphosis observed by Barrande 

 in so many of his Primordial forms. The little disk, not more than 

 half a line long (fig. 66), shows, when magnified (fig. 6 a), no trace of 



