1871.] HICKS FOSSILS FROM ST. DAVID's PKOMOKXORT. 401 



rather blunt. Differs from Theca penulUma and Theca cornigata in 

 having a smooth surface, and from Theca stiletto in being a larger 

 and wider form, and with a blunt extremity. 



LrNGTJLELLA PEiM^vA, Hicks. PI, XV. figs. 13, 14. 



Half an inch in length and about ^ of an inch in width. Some 

 of the valves show a tolerably convex form, and are marked with 

 concentric lines of growth ; most, however, are much compressed 

 and drawn out of form by the cleavage which has affected the beds 

 in which they occur. It is altogether a much larger species than 

 Lingulella feri'uginea, which also is found in the same beds. It is 

 moderately plentiful in the red beds at the base of the purple sand- 

 stones at Caerfai, Nun's Well, and Forth Clais harbour, on the coast 

 to the south of St. David's ; but as the beds in each case are much 

 cleaved, good specimens are seldom found. 



Leperditia ? CAMBRExsis, Hicks. PI. XV, figs. 15-17. 



Valves about 5 of an inch long, by about ^ of an inch in width. 

 Some of the specimens show a reticulated ornamentation entirelj' 

 distinct from the ordinary lines of growth in a Lingulella, which makes 

 it probable that they belong to the genus Leperditia. In other 

 respects the characters are rather indistinct ; and though specimens 

 are very plentiful in the red beds along with Lingulella primceva, 

 the cleavage has so affected them that it becomes difficult to recog- 

 nize their true form, or to note any special characters, 



Protospongia ? MAJOR, Hicks. PL XVI. figs. 14-18. 



The specimens figured under this name I have possibly incorrectly 

 referred to the genus Protospongia ; but as they approach nearer in 

 character to that genus than to any other yet described from the 

 earlier rocks, I may be pardoned for doing so in preference to making 

 a new genus, where the nature of the fossil is so indistinct. The 

 specimens, however, have very definite characters, and are entirely 

 distinct from those markings so common in the Cambrian rocks, and 

 usually classed together as worm-tracks. In many cases the lines 

 cross each other at sharp angles ; at other times a branching appear- 

 ance is given ; nearly all appear as if two flattened fibres were joined 

 together longitudinally, one being wider than the other. At present 

 only a few associated beds, almost immediately below those con- 

 taining Plutonia Sedgwickii, have yielded these fossils ; but in them 

 the markings are very plentiful, covering, indeed, almost the whole 

 surface of the beds. One specimen, however (fig. 18), was dis- 

 covered by me some time since in the " Menevian group." F^. 19 

 represents Protospongia'i Jlahella, Hicks, a Menevian species, but 

 placed here for comparison ; it certainly in some characters resembles 

 Protospongia ? major, and is most likely connected with it generi- 

 caUy. Fig. 20 represents P. fenestrata, Salter, also a Menevian 

 species, and the first described of the genus. In this species the 



VOL. XXVTI, PART I. 2 F 



