part I] CAMBRIAN HORIZONS OF COMLEY. 361 



Salterella (?) striata, sp. nov. (PL XXIV, fig. 45.) 



Type-specimen [139]. 



Diagnosis. — Shell a small, tapering, curved tube with elliptical 

 aperture ; axes in the proportion of 1 to - 6, rate of taper 1 in L8, 

 equivalent apical angle 32° ; shell-substance calcareous, thick, and 

 strong ; exterior marked with eight or more constrictions (which are 

 reproduced on the interior) and numerous fine radiating striae ; no 

 lines of growth seen. 



Dimensions. — Height=2 mm. ; diameter =L 7 mm. ; length = 

 3 mm. 



Observations. — Owing to the absence of any "obvious cone- 

 within-cone structure such as characterizes the type-species 

 8. rugosa, the reference of these two species to Billings's genus is 

 made with reserve. The thick calcareous shell and bent conical 

 form indicate a relationship with S. curvata and Serpitlites mac- 

 eullochi (see p. 359). On the other hand, Salterella striata has 

 points of resemblance with Helcionella and Scenella. 



Locality and horizon. — Comley, Lower Cambrian. Both 

 species are found in the Protolenus Limestone, horizon Ac 5 . 



Hyolithellus Billings. 

 Hyolithellus micans Billings. (PI. XXIV, figs. 19-21.) 



Hyolithellus micans Billings, 1872, 'Canadian Naturalist' n. ser. vol. vi, p. 215. 



Hyolithellus micans Billings, Walcott, 1886, U.S. Geol. Surv. Bull. 30, p. 142 

 & pi. xiv, figs. 2,-2 a-2e. 



Hyolithellus micans Billings, Shaler & Foerste, 1888, Bull. Mus. Comp. Zool. 

 Harvard, vol. xvi, p. 34 & pi. ii, fig. 23. 



Hyolithellus micans Billings, Walcott, 1890, 10th Ann. Rep. U.S. Geol. Surv. 

 p. 624 & pi. lxxix, figs. 1, 1 a-1 e. 



Hyolithellus cf. micans Billings, Lapwortli, 1891, Geol. Mag. p. 532. 



Hyolithellus micans Billings, Matthew, 1899, Bull. Nat. Hist. Soc. New Bruns- 

 wick, xviii, p. 192 & pi. ii, figs, la-1 d. 



Hyolithellus micans Billings, Matthew, 1899, Trans. Roy. Soc. Canada, vol. v, 

 sect. 4, p. 109 & pi. vi, figs, la-l d. 



Hi/olithellus micans Billings, Grahau, Occ. Pap. Boston Nat. Hist. Soc. vol. iv, 

 " pt. 3, p. 658 & pi. xxxii, fig. 12. 



Short lengths of tubes with black shining surfaces are of 

 frequent occurrence at Comley, and, although they assume many 

 aspects, there are no well-deiined characters to separate them one 

 from the other or from Billings's species. They occur at many 

 horizons, ranging from Ab 5 in the Lower to B'b L in the Middle 

 Cambrian. In section they are circular, the surface may be 

 smooth, or annulated with lines or bands of growth ; they are most 

 frequently straight, but sometimes sinuous (tig. 20) or even 

 strongly curved (fig. 19) and they show very slight traces of taper. 

 The diameters vary from 1 to 2 - 5 or even 3 millimetres. 



In thin sections the tube is seen to consist of one thin layer of 

 chitinous material, which must have been comparatively strong 

 and resistant, for the specimens rarely show any sign of collapse 

 or crushing. 



Locality and horizon. — Comley, Lower and Middle Cam- 

 brian ; from horizons Ac p Ac 2 , Ac*,,, Ac 4 , Ac 3 , Ad, Ba i; Ba 2 , Ba 3 , 



