274 APPENDIX TO THE SUPPLEMENTS TO 



36. Rhynchonella Beneckei, Haas {?). Dav., Appendix to Supplements, Vol. V, PI. 



XX, figs. 8, 9, 9 a, 10, 10 a. 



Rhynchonella Beneckei, Haas. Brach. d. Juraf. v. Alsass-Lothringen,pl. iv, figs. 3, 

 C— 8 (1, 2,4,5), 1831. 

 — — S. S. Buchnan. Brach. from the Inf. Ool. of Dorset, Proc. 



Dorset Nat.-Hist. Club, vol. iv, p. 51, 

 1882. 



Mr. S. S. Buckman refers to Haas's species some specimens of a very variable 

 Rhynchonella which he obtained from the Inferior Oolite of Bradford- Abbas in Dorset. 

 He says : " Dr. Haas quotes this species from the Middle Lias, or what he calls 

 Costatusschichten, which he places just above the Margaritatusschichten. From blocks of 

 stone in the Yeovil Sands (zone of Lytoceras Jurense), I have obtained several specimens 

 which agree exactly in all respects with the figures (3 and 6 — 8) given by Dr. Haas of 

 Rhynch. Beneckei. Specimens agreeing with 1, 2, 4, and 5, I have, however, not seen, 

 and therefore have put them into brackets in quoting it. Dr. Haas, however, takes as 

 his typical examples of his species figs. 3 and 7, with both of which our specimens agree 

 exactly. 



" The specimens from this district possess two, three, and four ribs on the mesial 

 fold, and the height of them varies considerably. In young specimens the ribs are flat in 

 proportion, and increase in height faster than the shell grows in size, but in specimens of 

 the same size the height of the ribs is often variable. 



" This species is, as it were, between Rh. cynocephala, Rich., and Rh. subangulata, 

 Dav., but in general the mesial fold is not so raised as in either of them. Its ribs also 

 do not extend more than half way up from the base of the shell. As far as I have been 

 able to observe, the deltidial plates of Rh. cynocephala are far larger in proportion than 

 those of Rh. Beneckei. The far greater number of ribs, continued, too, all up to the beak, 

 distinguishes Rh. subangulata from this species. Dr. Haas quotes it from Uhrweiler and 

 Nuelhausen in Alsace ; Zocourt and Luppy in Lorraine ; also Essey and They (Meurthe 

 and Moselle). This species seems properly to belong in this district to the zone of Am. 

 Jurensis." I am very uncertain with respect to this identification, and give it on Mr. S. 

 S. Buckman's authority. 



