




16 MIDDLE CAMBRIAN. 
Caseiand Reference to McCoy’s 
Column of' 3 3 j Names and References; Observations, &c. Localities and Numbers. 
Drawers. Synopsis: and Figures of Genera. 
Pteropods. PTEROPODA (Sea-Butterflies). 
Gi Theca operculata, Salter (Mem. Geol. Surv. | Tyn-y-llan, &c.,near Borth, 
Vol. 11. pl. 10, figs. 22—24). Most of the | Portmadoc. (Mr. Ash.) 
species of fossil Theca are operculated. The | b. 335. (Pres. Mr. Hom- 
living Pteropods nearest them in shape are | fray.) 
not so, but several of the spiral kinds have 
an operculum. (ib. p. 351 and note). 
Gi Theca bijugosa, Salter (ib. pl. 10, figs. 19, 20). | Borthwood,  Portmadoc. 
The species differ in proportionate length | (Mr. Ash.) b. 334, Tyn-y- 
and breadth, and in the longitudinal ridges; | dre, do. figured specimen. 
most are smooth. (Mx. Homfray.) 
| Theca arata, Salter (ib. pl. 10, figs. 15 and 21). | [Portmadoc.] 
| May easily be obtained. 
Brachiopods. BRACHIOPODA. 
Gi Lingulella lepis, Salter (Davids. Sil. Brach. in | Tremadoc. (Mr. Homfray.) 
Pal. Trans. t. 3, figs. 53—59). 
| Trilobites and Phyllopods. e2. Upper Tremadoc Slate (Salter, 1857). 
Gi CRUSTACEA (Phyllopods and Trilobites), 
Lingulocaris lingulecomes, Salter (Mem. Geol. | . 98 Garth, Portmadoc. 
Surv. Vol. m1. pl. 10, figs. 1. 2). A bivalve (Mr. Ash.) b. 327, figured 
crustacean, allied to the Ceratiocaris of the specimen. (Pres. Mr See 
Silurian rocks, and also to the living Lim- fray.) 
nadia. 
Gi Ceratiocaris? latus, Salter; front segments of | b. 299, Garth (figured spe- 



body very broad. Badly figured in p. 294, 
Mem. Geol. Surv. Vol. m1. as Hymenocaris. 
For genus, see Ludlow Rocks. 
Ceratiocaris ? insperatus, Salter (Mem. Geol. 
Surv. Vol. mt. p. 295, fig. 6). It is quite 
probably the tail portion of the preceding. 

cimen, Mr. D. Homfray). 
b. 343, Above Penmorfa 
Railway cutting, figured 
specimen, (Mr. Homfray.) 
