

58 UPPER CAMBRIAN. 
Gaeta a ESHER ue ON Names and References; Observations, &c. Numbers and Localities. 
Drawers. Synopsis: and Figures of Genera. 
Gl O. flabellulum, p. 219. Orthis, id. var. virgata, Salter, Mem. Geol. Surv. | b. 215, Coniston; b. 216, 
Ill. p. 336, pl. 22, fig. 3 (O. virgata, Sil. Syst. | Applethwaite ; Gelligrin, 
pl. 20, fig. 15), Siluria, 2nd ed. pl. 5, fig. 9. | Bala; Alt-yr-Anker, Mei- 
fod, Montgomeryshire (as 
O. vigida). 
Gl O. var. a. calliptycha, p. 215. | Orthis, id. var. calliptycha, McCoy. A pretty | b. 214, Llansantfraid, Glyn 
variety with coarse ribs; the interspaces | Ceiriog. 
| | strongly ribbed with wire-like striz. 
| | 
Gl p. 214. | Orthis, id. var. Wallsalliensis, Salter (O. Wall- | b. 212, Rhiwargor (more 
O. rigida, p. 226. salliensis, Davidson. See Mem. Geol. Surv. | common in Llandovery 
Vol. 11. p. 337, pl. 22, figs. 6, 7. rocks). Gelligrin; Traws- 
coed; b. 211, Gaerfawr (as 
O. confinis). b. 213, Gaer- 
| fawr, Welchpool. 
Gi | p. 216 Orthis, id. var. crispa, McCoy (Sil. Foss. Irel, | a.158*, Bala; Blaen-y-cwm, 
p. 29, t. 3, fig.10, A remarkable small spe- | Nantyr; a. 158, Helms- 
cies, with strong waves and ridges of growth | gill, Dent. 
| decussating the ribs. 
Gl p. 219. | Orthis flabellulum, Sow. (Salter, Mem. Geol. | a. 150, Bodean, Pwllheli, 
Surv. lL. p. 338, pl. 21, figs. 9—16). A hand- | Bettws; Moel-y-garnedd, 
some Bala shell, with fan-like ribs 20 to 30. | W. of Bala; Gelligrin; Ca- 
der Dinmael ; Blaen-y-ewm, 
Nantyr; Snowdon top; 
Llangedwyn; Llanwddyn; 
Meifod; Moel Uchlas. 
Gl O. sarmentosa. | Orthis flabellulum, var. finest ribs (Salter, Mem. | b. 219, Llyn Ogwen, abun- 
Pl. 14, figs. 25—28, p. 227. Geol. Surv. m1. pl. 21, fig. 17), looks like a | dant. 
distinct species, but is easily traceable into 
O. flabellulum. 
N.B.O. sarmentosa, McCoy, Sil. Foss. Ireland, is 
the O. testudinaria, distorted by cleavage. 
Gl | PL 14, figs. 41, 42, p. 223. | Orthis porcata, McCoy (0. occidentalis, O. sinu- | b. 221, Coniston; High 


ata, &c. of Hall. Salter, Mem. Geol. Surv. 
Vol. m1. p. 338, pl. 19, fig. 4). Very like ex- 
treme varieties of O. flabellulwm, from which, 
when fine-ribbed varieties of both are com- 
pared, it is extremely difficult to separate it. 
The interior characters are alike in both. 

Haume; Dalton; a. 155, 
Horderley; Corwen; Bala; 
Llansantfraid,Glyn Ceiriog; 
Meifod;a.154, Alt-y-gader; 
Alt-yr-Anker; Llanfyllin 
(Pen - y - Park), Corwen. 
Common in all varieties, 
N. Ireland. 
