34 OEDOVICIAN AND SILURIAN BELLEROPHONTACEA. 



Ulricli and Scofield,^ in 1897, separated off the species described by Koken- as 

 B'ucanella [sic] esfltoiio under the generic name KoJcenia, and referred to it also a 

 new American species Kokenia costalis, Uh\ & Scof. Unfortunately the generic 

 name was pre-occupied, having been used by Holzapfel in 1895,^ as Bassler* has 

 pointed out, and the latter author has suggested the name Kol-enosiyira in its place. 

 Pernor does not record any members of it from Bohemia. The genus Kokenia is 

 mentioned amongst the Bucaniidoe in Zittel-Eastman's ' Text-book of Palaeon- 

 tology ' (2nd edit., 1913, p. 522). 



1. Kokenospira credibilis, sp. nov. Plate VI, figs. 12 — 14. 



Specific Clinrnrfers. — Shell globose, whorls broader than high. Umbilicus 

 deep, more than one-third the height of the shell in diameter ; umbilical 

 edges subangular ; umbilical slopes very steep. Outer whorl large, rapidly 

 increasing in size, about three times as wide as high, laterally overhanging but 

 not concealing most of the inner whorls ; dorsum broad, gently convex, more or 

 less flattened. Slit-band wide. Mouth transverse, as wide as, or wider, than total 

 height of shell. Surface of shell ornamented with revolving thread-like lines, 

 parallel to slit-band, near which they are crowded and faint, but becoming stronger 

 and wider apart towards and upon umbilical edge. 



Dinicnsiovs. — Height of shell, 12 — 15 mm. 



Horizon. — Llandovery Series. 



Localities. — Gas Works, Haverfordwest ; ? The Frolic, Haverfordwest. 



Remarks. — This species is allied to the better known K. lingualis and K. 

 mullochensis from Girvan (see below). All the specimens, except a few internal 

 casts, are more or less crushed and distorted, and it does not seem possible to 

 separate those from the Gas Works and the Frolic. All the material was obtained 

 by Mr. Turnbull, and is in the Sedgwick Museum. 



2. Kokenospira euphemoides, sp. nov. Plate VI, fig. 15. 



Specific GJiaracfers. — Shell sul)globose, composed of a few transverse rounded 

 whorls. Umbilicus deep, rather less than one-third the diameter of the 

 shell. Outer whorl rounded, convex, wider than high, Avith strongly arched 



' Ulricli and Scofield, op. elf., pp. 849, 882. 



2 Kokeu, ' Neues Jalirb. f. Miner.,' suppl. vol. \'i (1889), p. 389, pi. xiii, figs. 1, la. 



^ Holzapfel, "Obere Mitteklevon Ehein. Geb." ('Abhandl. k. preuss. geol. Landesanst.,' n.s., pt. 16, 

 1895), p. 159. 



■' Bassler, Bull. 92, U.S. Nat. Mus., 'Bibliogr. Index Anier. Ordov. Silur. Foss.,' vol. i, 1916, 

 p. 687. 



