72 CANADIAN iMICRO-PALyEONTOLOdY. 



B. FKOM TIIK SILURIAN liOOKS. 



1. PllIMlTIA MIINDULA, .loilOH. 



Beyrichia mundula ,,] ones. Ann. Map. Nut. Hist., sor. 2, vol. XVT, 1855, p. <)(), 



pi. V, li^'. 23 ; p. 174, pi. xvi, li^s. 2S-:U, and variety, fip. 26 

 (" /). mriplrj-, var"). 



Primitid mundxda, .lonos and lloll. Op. cit., ser. 3, vol. XVI, 18(15, j). 41!) ; hot. (! 



vol. HI, 188J), p. ;)7(), lip. 2 (wood-cut), pi. xvi, lips. (J and 

 9, pi. xvii, Up. 1, and p. :>78 (variotioH), pi. xvi, ligs. 1, I, 

 5, 7, and 8. 



Pri mi tia inundida, .]oim9. Trocoed. Geol. Assoc, Pal. i>iv. Kntom, 18Ui), p. xiii, 



lig. 2 (a rather scaphoid form). 



Ah mentioned in the (^uart. Joiirn. Geol. Soc, vol. XL VI, hSDO, p. 

 552, Frimitia mimdula, Jones, an a nrnall variety, occui'h in a liino.slone 

 atStonehouHO Brook, Arinaig. This is ])robal)ly the Primitia mentioned 

 at p. 492, lines 38-41, op. cit., vol. XXVI, 1870, but not (he spocios re- 

 ferred to in lines 36-37. 



Another Primitia is associated with it, namely, Primitia ovata (?), 

 •Tones and IIolI, an obscui'O oval cast; probably the same form as that 

 referred to in ' Geol. Mag.,' 18S1, ]). 341. 



2. Beyriciha ^quilatera, Hall. 



PI. II, i'ltr. (;. 



Beyrichia equilaiera, HnW. Canadian Naturalist and G(H)lopist, vol. V, 18()(), p. 



158, fig. 20. 

 Beyricliia €(juUutera, Dawson. Acadian Gcolopy, 2nd (^dit., 18()S, ]>. (lOS, dp. 217; 



:5rd edit., 1878, p. ()09, fip. 217. 

 Beyrichia xquilatera, Jones. Quart. Journ. Geol. Soc , vol. XLVI, 181K), p. 18, pl. 

 • ii, fip. f), an<l j). 552. 



PI. 11, fig. G. Length 1*5 (hinge-line 1 -5), height 1 "l. 



il. J. (I. S., 1890, j)l. ii, lig. r,: Length -H (hing(;-line -8), height 



.52 mm. 



This is the best specimen of />. a-quilatera (all easts) met with in lh(i 

 series sent by the G(H)logical Surveyor (Janadji loi* examination. Of 

 its three lobes the smallest is in fi-ont and the laigest (gigot) lobe is 

 behind. The latter curves venti-ally to meet, the base of the mi<ldl(5 

 lobe, and the front lobe cui-ves away from the base of tin; last. Neithei* 



