












70 UPPER CAMBRIAN. 
Cc d ’ 
Gsiaimn ct ee ee BHOGEE Names and References; Observations, &c. Numbers and Localities. 
Drawers. | Synopsis : and Figures of Genera. 
Gm p. 291. Raphistoma equalis, Salter (Siluria, 3rd ed. | Alt-yr-Anker, Meifod. 
(Plewrotomaria lenticularis.) Foss. 40, fig. 2). It is found that the pro- 
portions of the whorls in this species differ 
from those of the May Hill Sandstone form. 
Gm Maclurea, p. 800. Raphistoma? (or Helicotoma) macromphala, | a. 168, Craig Head, Gir- 
TEAR, th to, ravens 4, McCoy sp. van. 
Gm p. 302. Loxonema , sp. A large species, much | a. 177, Cefn-y-coed Lime 
like those from rocks of the same age in | quarry; Mynydd Fron 
Sweden. Frys, Chirk. 
Gm Holopella , Sp. ; Troutbeck. 
These elongate Turritella-like shells are pro- 
bably members of the Pyramidellidz, not 
Litorinde. 
Gm PL1 K, fig. 32, p. 304. Holopella monilis, McCoy. a. 181, Selattyn Road, near 
Chirk. 
Cephalopoda (Tetrabranchiata). 
The shells allied to Nautilus are of the greatest 
variety and abundance in the slate rocks. 
Straight, curved, coiled, or involute, they 
exhibit every change of form which is ex- 
hibited in later formations by the Ammonite 
group. Orthoceras and its subgenera are 
the common forms in the Bala rocks, while 
Lituites, Trochoceras, and Phragmoceras, 
abound in Silurian strata. 
Gm Pl. 11, figs. 28, 29, p. 318. | Orthoceras vagans, Salter (Mem. Geol. Surv. | a. 175, Coniston; Trout- 
jj AS =F Ill. p. 356, pl. 24, figs. I—5). A common | beck; a. 175*, Dufton, in 
\ IM fossil with distant septa. It ranges to | green slates; (Prof. Hark- 
EEE > Portugal and Sweden. ness) Rhiwlas, Bala, 
chara Orthoceras, smooth species. Holbeck gill (in nodules). 
Gm Pl. 11, fig. 30, p. 316. Orthoceras politum, McCoy (Quart. Journ. Geol. | a. 172, Glenquhaple. 
Soc., Vol. 7, pl. 10, figs. 5, 6). 
Gm do. Orthoceras, smooth species, with closer septa | Pusgill, Dufton (green 
than O. vagans above quoted. slate). 
Gm p: 319. Orthoceras bilineatum, Hall, Pal. N. York, t.43, | Coniston (? Upper Bala). 


f. 2, 3 (Siluria, 3rd ed. p. 200). 

a. 172*, Ardwell, Girvan. 
