PLATE XXXI. WLI 
LINGULELLA? PRIMEVA Hicks (p. 527). 
Ficures 5 and 5a. Ventral? valves from the Middle? Cambrian Caerfai group (see Locality 366c), south of St. 
Davids, South Wales. Copied from Davidson [1883, Pl. XVII, figs. 34 and 33, respectively]. Figure 
5a represents the type specimen, Davidson’s figure being a copy of the one given by Hicks [187], 
Pl. XV, fig. 14]. 
LINGULELLA DAvist (McCoy) (p. 489). 
[Pl. XXX, figs. 2 and 2a.] 
Fieures 6 and 6a. Distorted ventral valves from ‘‘Lingula flags, Penmorfa, Tremadoc’”’ (see localities 366k and 3661), 
Merionethshire, North Wales. Copied from Davidson [1866, Pl. IV, figs. 10 and 11, respectively]. 
6b. Distorted ventral valve from Locality 317b, Middle Cambrian, at Bellewstown, County Meath, Ireland. 
Copied from Davidson [1866, Pl. IV, fig. 12]. 
6c. Enlargement of the area of a cast of a ventral valve from Locality 366a, Upper Cambrian shales, 6 miles east 
of Ffestiniog, Merionethshire, North Wales. U.S. Nat. Mus. Cat. No. 51740a. 
6d. Cast of the interior of a distorted ventral valve associated with the specimen represented by figure 6c. 
U.S. Nat. Mus. Cat. No. 51740b. Specimen figured by Walcott [1898b, Pl. XX VII, fig. 2] as Obolus 
(Lingulella) davisti. 
6e. Cast of the interior of a dorsal valve, showing the characteristic muscle scars of the genus. Locality 366n, 
Upper Cambrian shales at Portmadoc, Merionethshire, North Wales. U.S. Nat. Mus. Cat. No. 
35239a. Specimen figured by Walcott [1898b, Pl. XX VII, fig. 4] as Obolus (Lingulella) davisii. 
6f. Cast of the interior of a ventral valve associated with the shell represented in figure 6e, showing the out- 
lines of the visceral cavity and the vascular sinuses. U.S. Nat. Mus. Cat. No. 35239b.. Specimen 
figured by Walcott [1898b, Pl. XXVII, fig. 1] as Obolus (Lingulella) davisii. 
6g. Cast of the interior of a ventral valve in which the characteristic punctate surface of the interior of the shell 
is shown by the large papillee scattered over the surface. Locality 366a, Upper Cambrian shales 6 
miles east of Ffestiniog, Merionethshire, North Wales. U.S. Nat. Mus. Cat. No. 51740c. 
6h. Cast of a distorted dorsal valve associated with the shell represented in figure 6g, preserving the impressions 
of the transmedian and outside Jateral muscle scars. U.S. Nat. Mus. Cat. No. 51740d. Specimen 
figured by Walcott [1898b, Pl. X XVII, fig. 5] as Obolus (Lingulella) davisii. 
