CONULARIA PLANISEPTATA. 35 



Horizon and Localities. — Upper Ludlow : Brigsteer ; Benson Knot ; Under- 

 barrow; Usk, Monmouthshire; Wkitcliff, Ludlow; etc. 

 Type. — Sedgwick Museum, Cambridge (reg. no. b 59). 



Conularia complanata, sp. nov. Plate IV, figs. 12 — 14. 



Diagnosis. — Shell large, tapering more rapidly near the apex. Cross-section 

 an ellipse. Faces equal, gently convex; apical angle about 15°, but the sides 

 nearly parallel, except towards the apex. Marginal grooves shallow, with angular 

 base ; facial grooves absent. Aperture unknown ; apical septum convex, shallow. 

 Ornamentation fine; ridges low (17 in 5 nun.), forming an angle of about 

 160° towards the aperture, diminishing to 140° towards the apex ; studded with 

 small, round, prominent tubercles. Furrows smooth, or more often slightly striated. 



Dimensions. — Length about 150 mm. Greatest width of face, 25 mm. 



Description. — In Carboniferous rocks the species is comparatively abundant, 

 but its preservation is nearly always bad. The shell often reaches a large size, 

 and the prismatic form towards the aperture is well seen. The spacing of the 

 ridges is very uniform for the greater part of the shell, but near to the aperture 

 the ridges become very crowded. There is an imperfect specimen from the 

 Devonian of Padstow, Cornwall, which may belong to this species (British Museum 

 [Nat, Hist.], G. 8229). 



Affinities. — This species resembles most closely 6'. subtilis, from which it is 

 distinguished by the large size, the absence of the facial groove, and the wide 

 angle of the transverse ridges. 



There is a specimen in the British Museum (Nat. Hist.), reg. no. G. 9030, from 

 the Carboniferous Limestone of Stonyhurst, Lancashire, which differs from the 

 foregoing in some important points, but the preservation is so bad and the 

 specimen so imperfect that no satisfactory diagnosis can be given. The characters 

 which can be determined are : Marginal grooves very shallow. Ornamenta- 

 tion fine ; ridges very narrow, evenly spaced (14 in 5 mm.), forming at the 

 aperture broad curves, which give place towards the apex to perfectly straight 

 horizontal lines. Ridges appear to be tuberculated with widely separated round 

 tubercles ; furrows smooth. Length of portion, 82 mm. 



Horizons and Localities. — Devonian : Padstow, Cornwall (?). Carboniferous 

 Limestone : Bristol ; Oreton and Farlow, Salop, etc. 



Type.— British Museum (Nat. Hist.) (reg. no. G. 176(56). 



Conularia planiseptata, sp. nov. Plate V, figs. 1, 2. 



Diagnosis. — Shell small, tapering uniformly, or slightly more rapidly near the 

 apex. Cross-section rhombic or elliptical, with the longer diameter more than 



