156 E. S. Gobbold — Cambrian Hyolithidai from Hartshill. 



Bellerophon, and it is possible that it should be relegated to a new 

 genus and placed among the Heteropoda. The general form is 

 suggestive of the ventral valve of an elevated Brachiopod, but the 

 notch being at the anterior margin cannot be a pedicle opening. 



Pelagiella, Matthew, 1 and Watsonella, Grabau, 2 have similar 

 notched margins, but are very different in other respects. 



Horizon and Locality. — Lower Cambrian : the red sandy limestone 

 of Woodlands Quarry, Hartshill. 



Stenotheca (Salter), Grabau & Shinier. 



Stenotheca abrupta, Shaler & Foerste (?). (PL IY, Figs. 28, 29.) 



Stenotheca rugosa, var. abrupta, S. & F., Bull. Mus. Comp. ZooL, vol. xvi, 



p. 29, pi. i, figs. 9a, fir, 1888. 

 S. (?) rugosa, var. abrupta (S. & F.), Walcott, Tenth Ann. Eep. U.S. Geol. 



Surv., p. 617, pi. lxxiv, figs. 6, 6a, 1890. 

 S. abrupta (S. & F.), Grabau, Occ. Papers Boston Nat. Hist. Soc, vol. iv, 



pt. iii, p. 637, pi. xxxi, figs. 12a-c, 1900. 



A few internal casts agreeing closely with "Walcott's figures seem 

 to indicate the presence of this form. 



They show from six to ten rounded corrugations; the section is an 

 elongate oval with the axes in the proportion of 1 to '5 ; the apex is 

 curved over so as to stand approximately above the posterior margin 

 of the aperture. Exterior not observed ; no thickening of the ventral 

 margin, such as is spoken of by Grabau (op. supra cit.) has been 

 detected. Dimensions (of largest specimen) : length 5, width 2"5 r 

 height 4 - 5 mm. 



In the absence of good exteriors of these shells it seems doubtful 

 whether they should not be referred to Hclcionella, the genus pro- 

 posed in 1910 by Grabau & Shiiner for forms congeneric with 

 Ifetoptoma rugosa, Hall. It is consequently necessary to give the* 

 specific reference with reserve. 



Locality and Horizon. — Lower Cambrian : the red sandy limestone 

 of Woodlands Quarry, Hartshill. 



L AMELLIBBANCHIAT A . 



Fordilla, Barrande. 



Fordilla troyensis, Barrande (?). (PI. TV, Fig. 33.) 



Fordilla troyensis (Barrande), Walcott, Bull. U.S. Geol. Surv., No. 30, p. 125, 



1886. 

 Walcott, Tenth Ann. Eep. U.S. Geol. Surv., 

 p. 615, pi. lxxiii, figs. 2, 2a-c, 1890. 

 ,, ,, ,, Grabau, Occ. Papers Boston Nat. Hist. Soc.,. 



vol. liv, pt. iii, pp. 610, 611, 633, 1900. 



A single shell occurs with the Hyolithidse from Woodlands Quarry 

 agreeing in many respects with Walcott's figures for this species. . 



It appears to be the somewhat worn exterior of a left valve, and is 

 about 3 mm. long with the umbo situated a little in advance of the 

 mid-length. No radial stria? are preserved, and the concentric lines 

 of growth are not so thickly set as those shown in Walcott's figures. 



: Trans. N.Y. Acad. Sci., vol. xiv, p. 131, 1895. 

 2 Op. cit., p. 631, 1900. 



