SO APPENDIX. 



ADDITIONAL SPECIES. 



Terebratula Etheridgii, Dav. Appendix, PI. A, fig. 7 — 8. 



Diagnosis. Shell inequivalve, almost as wide as long, and more or less obtusely five-sided. The dorsal 

 valve is moderately convex at the umbo ; but thence it forms a nearly straight mesial line to the front, 

 in the approximation of which the lateral portions of the valve become much excavated, producing a mesial 

 fold of moderate dimensions. The ventral or dental valve presents a longitudinal sinus, commencing 

 towards the middle of the shell and. extending to the front, the margin forming a convex curve, indenting 

 considerably that of the opposite valve ; lateral margins very flexuous ; beak short, incurved, and truncated 

 by a foramen of moderate dimensions, placed contiguous to the hinge-line and umbone of the socket valve. 

 External surface smooth, marked only by a few concentric lines of growth. Loop unknown, but probably 

 short. Dimensions variable : length, 13 lines; width, 12^ lines; depth, 8 lines. 



11 „ 11 „ 7 „ 



Obs. Four examples of this shell are preserved in the Bristol Institution Museum, labelled "Dundry" 

 (probably Inf. Oolite ?), they differ from the Jurassic Terebratulee described in this work by the shape and 

 character of their mesial fold. 



I have named it after Mr. Etheridge, to whom I feel greatly indebted for the liberal communication of 

 a great number of interesting specimens belonging to the Bristol Institution Museum. 



Plate A, fig. 8 — 9. Two examples from Dundry, in the Bristol Institution Museum. 



Several examples of a Terebratula intermediate in shape and character between Ter. Etheridgii and 

 T. equestris (PI. A, fig. 7 and 9) have been lately discovered by Dr. Wright, in the Perna bed (top stratum 

 of the Inf. Oolite), at Cold Comfort, eight miles from Cheltenham, or in that zone characterised by the 

 Trigonia costata, Cueullae ornata, Area elegans, Myopsis rotunda, Ammonites Parkinsoni, &c. In shape it 

 is longer than wide ; valves equally globose, with the greatest depth near the centre of the shell ; margins 

 sinuous, front nearly straight and angularly elevated ; beak short, incurved ; foramen small, circular, and 

 separated from the hinge-line by a deltidium in two pieces ; surface smooth, with obscure lines of growth. 

 Average dimensions : length, 8£ lines ; width, 1\ lines ; depth, 6 lines. These specimens have been minutely 



examined by Dr. Wright, Mr. Lycett, and Mr. S. P. Woodward, and pro- 

 nounced different from those hitherto described from our British Oolites. 

 Should this shell turn out to be really new, and distinct from T. Etheridgii 

 and T. equestris. as it is believed to be by the above-mentioned gentlemen, I 

 should propose for it the name of its discoverer. It must likewise be 

 mentioned that a shell bearing some resemblance to the one under descrip- 

 tion has been discovered by Mr. Lycett in the marl bed of the Inf. Oolite near Minchinhampton. 



In PI. A, fig. 9, will be found represented a terebratula, labelled " Fullers Earth, Grip Wood," by 

 Dr. W. Smith, and now in the British Museum. Mr. Woodward seems doubtful both as to the locality and 

 stratum, and thinks that it may perhaps represent Ter. equestris, D'Orb. ('Prodrome,' vol. II, p. 24, 

 1850?) ; but, as the French author's species is simply mentioned, without sufficient description or figure, 

 all I can do at present is to point out the existence of the specimen, and recommend further researches to 

 be made in Smith's locality. 



I have likewise represented in PI. A, figs. 10 to 13, a series of specimens forwarded from the Bristol 

 Institution Museum, with the sole indication, "Dundry." They may, perhaps, only constitute a variety of 

 Ter. sphceroidalisl, but possess certain peculiarities not known to me in that species. I have figured several 

 of the specimens, in the hopes that some positive information as to its strata and locality may be obtained. 



