Yol. 51.] OF THE MID-COTTES WOLDS. 447 



shell which occurs in the Oolite Marl of the Cotteswolds, the 

 preceding article gives information. 



It is doubtful if either this or the last shell have any right to 

 the generic term Glossothyris which was proposed for the Nucleatae, 

 type G. nucleata, Sch. (sp.), but they seem to have less claim to be 

 called Terebratula. They appear to be genetically related to simplex, 

 J. Buckm., and Leesi, S. Buckm., which preceded them in time, and 

 to galeiformis, M'Coy, and provincialis, E. E. Desk, which were 

 their contemporaries. In fact, provincialis appears to be nothing 

 more than a derivative of Brebissoni, while Brebissoni and curvifrons 

 may be derivatives from simplex ; galeiformis seems to be a biplicate 

 derivative of curvifrons. 



There is a small allied shell in the Upper Lias with a slightly 

 sulcate imperforate valve, usually confounded with and called 

 ' Waldheimia Lycetti.' As it lacks the septum, however, it does not 

 belong to the Waldheimiidoe (Magellaniidse). It may be the parent 

 of the whole series. 



(5) ACANTHOTHYRIS. 



In the course of these investigations several species of Acantho- 

 thyris which are new to the Cotteswolds, and mostly new to science, 

 have been discovered in the ' intervening beds.' In the Witchellia- 

 grit there is a species not unlike a small race of Acanthothyris 

 paucispina, B. and W., and a finer-ribbed form somewhat like tenui- 

 spina, Waagen. In the Gryphite-grit (non-gryphseiferous beds) of 

 Stroud Hill (see p. 396) there are some specimens somewhat like 

 Acanthothyris Crossi, Walker, besides a larger, more globose form. At 

 the same horizon (Bird-in-Hand) a less globose, more coarsely costate 

 form was found (see p. 402). At Buckholt Wood in the Buchmani- 

 grit a broad, coarsely costate, rather flat species was obtained (see 

 p. 405), and at Charlton Common in the BucJcmani-ma,rl (Bed 5, 

 p. 413) was found an almost entirely globular species, with the spines 

 in neat, regular rows, the first some little distance from the beak : 

 altogether a most distinct form. Thus there are some six species, of 

 which four or five are probably new. This, in a country which has 

 received so much attention as the Cotteswolds, is a somewhat large 

 addition to a limited group such as Acanthothyris. 



(c) Rhynchonella, sp. n. 

 Rhynchonella cymatophora, 1 S. Buckman. 



1882. Wiynchonella gingensis, S. Buckman, non Waagen, ' Brach. Inf. Ool.,' Proc. 

 Dorset Nat. Hist. & Ant. Field-Club, vol. iv. p. 45. 



1884. Shvnchonella gingensis, Davidson, ' Mouogr. Brit. Fossil Brachiopoda,' 

 vol. v. Pal. Soc. App. to Suppl. pi. xx. figs. 1, 1 a. 



A Wiynchonella of the tetrahedra-type with a very gibbous dorsal 

 (imperforate) valve, its mesial fold bearing five to six well-marked 



1 Kv/xa, wave ; 0opos, bearing. 



Q. J. G. S. No. 203. 2 i 



