350 MB. £ S. COBBOLD OX THE [vol. lxxvL 



as such by A. W. Grabau (1900, p. 655). G. Holm (1893, p. 30) 

 places Syolithus communis under Orthotheca, and other writers 

 seem to have followed him. 



S. strettonensis resembles S. primcevus Groom * from Malvern, 

 and may indeed be identical with it. Dr. T. T. Groom is, however, 

 uncertain whether his species is an Orthotheca or a Syolithus 

 sensu stricto; and, until specimens elucidating this point are forth- 

 coming, it seems advisable to describe the Comley form as a distinct 

 species, lest a similar confusion to tbat mentioned above should 

 arise. 



Locality and horizon. — Tbe Cwms, Church Stretton (a con- 

 tinuation of the Comley Cambrian in a south- westerly direction). 

 Lower Cambrian. From the greenish-grey sandstone, horizon Ab t 

 of the Road Quarry. 



The variety brevis Avas found in beds of the same horizon at 

 the north-eastern end of Caradoc Hill. 



Hyolithus (?) sculptilis, sp. nov. (PL XXIV, figs. 25-27.) 



Type-specimens [2583 & 2587]. 



Diagnosis. — Shell straight, or slightly tapering, sub-oval in 

 section, with one side rather less convex than the other, ratio 

 of diameters 1 to - 7 ; shell-substance of two layers — the inner 

 calcareous, thick, and smooth internally, the outer thin and covered 

 with short, parallel, transverse wrinkles arranged in longitudinal 

 rows that are separated by lines of plain shell ; occasionally two or 

 more rows will coalesce, but as a rule they remain distinct. The 

 wrinkles may be straight or crescentic, and sometimes those of one 

 row are set at a sharp angle with those of tbe contiguous row. In 

 one fragment, probably from the neighbourhood of the aperture, 

 the rows are traversed and replaced by continuous ridges or lines 

 of growth. 



Estimated dimensions. — Length = 30— 10 mm.; apertural 

 diameter = about 4 mm. 



Small fragments with the characteristic sculpture are plentiful 

 in the Protolenus Limestone ; in only one instance is the sectional 

 form seen, and in no case is there anything like a complete shell ; 

 on this account the generic reference is given with reserve. At 

 first sight the fragments suggest a reference to Conularia ; there 

 are, however, no re-entering suture-like lines such as are depicted in 

 Tate's figures of his species S conularoidesfi 



Locality and horizon. — Comley, Lower Cambrian ; from the 

 Protolenus Limestone, Ac 5 . 



Hyolithus sp. indet. Operculum (PL XXIV, fig. 29). 



An operculum, which cannot with certainty be referred to any 

 accompanying shell occurs in considerable numbers in the Proto- 

 lenus Limestone. 



1 1902, p. 110 & text-fig-s. 17-24. 



2 1891, p. 186 & pi. ii, figs. 1- In. 



