82 
Case and 
Column of 
Drawers. 
Reference to McCoy’s 
Synopsis: and Figures of Genera. 

Go 
Go 

Leptagonia, p. 248. 
a 

Leptena, p. 241. 
L. alternata, p. 233. 
L. quinquecostata, 
Pl. 14, f. 30, 31, p. 236 
(not fig. 32). 
Bivalves, 
Orthonotus semisulcatus, 
p. 275. 

UPPER CAMBRIAN. 

Names and References; Observations, &c. 
Numbers and Localities. 

Strophomena depressa, Sow. (8S. 
rhomboidalis of Wahlenberg. Da- 
vidson, Introd. to Class. Brach. pl. 
8, figs. 167—173). This weed of 
the Silurian and Cambrian rocks 
assumes fifty different shapes. 
Strophomena antiquata. Sow. (Silu- 
ria, 2nd ed. pl. 20, fig. 18). 
Strophomena, sp. Fine lines. So 
many are the species of this group 
in all parts of the world, that 
good internal characters are want- 
ed to discriminate them. 
Leptena sericea, Sow. (Siluria, 2nd 
ed, pl. 5, fig. 14). 
Leptena sericea, var. rhombica, Phill. 
Leptena transversalis, var. undu- 
lata, Salter (not the true quin- 
quecostata, for which see p. 64). 
Leptzna scissa, Salter, MS. A small 
and highly convex form, with the 
muscles deeply indented. (Silu- 
ria, 3rd ed. p. 210.) 
LAMELLIBRANCHIATA. 
Orthonotus sp. 
Ctenodonta (Nucula formerly), see 
p. 66. C. Hughesti, n. sp. Salter. 
Squarer and less ovate than the 
kindred Caradoc forms. 


Upper Bala proper. 

b. 400, Rhosfawr, N. 
of Glog, Llanfyllin. 
b. 405, S. of Llan- 
fyllin. 

Llandovery Group. 

b. 401, Allt Goch, 
Llanfyllin; b. 402, 
Mathyrafal; Penlan. 
Mathyrafal; a. 977, 
Lettyrhyddod, Llan- 
dovery (Mr Hughes). 
b. 404, Dalquorrhan, 
Girvan. 
b. 406, Mathyrafal; 
b. 407, Goleugoed; 
b. 408, Allt Goch. 
b. 409, Mathyrafal. 
b. 410, Craig Wen; 
b. 411, Cefn Rhyddan. 
a. 198, Mathyrafal, 
near Meifod. a. 196, 
Pen-y-Craig. 
a. 197, Pen-y-Craig. 
a. 189, Mullock. 
a. 979, Lettyrhydd- 
od, Llandovery (Mr 
Hughes). 
