JURASSIC AND TRIASSIC BRACHIOPODA. 211 



stronger ribs occupy the surface of each of the lateral lobes. Ventral valve not quite so 

 deep as the opposite one, with a sharply defined median sinus ; eight or nine short ribs 

 cover the surface of this valve, the beak of umbonal portion remaining smooth ; one or 

 two short ribs occupy the central portion of the sinus, the remainder the lateral portions 

 of the valve ; beak pointed, incurved, foramen situated under its extremity and margined 

 by small deltidial plates. 



Length 5, breadth 6, depth 3^ lines. 



05s. — Through the kindness of Dr. Fraas, of Stuttgard, and the late Dr. Oppel, I have 

 been able to examine typical German examples of this species from the lower portion of 

 the Middle Lias of Balingen and Ofterdingen. This species and Bh. Amalthei were 

 discovered by Dr. Fraas, and given by him to Professor Qtienstedt to name and describe. 

 I compared these German types with specimens from the upper portion of the Lower Lias 

 of the Aston cutting, Northamptonshire, in the Museum of the School of Mines, and with 

 others found by the Rev. F. Smithe in the Am. oxynoti Zone of the Lower Lias, at Church- 

 down, in Gloucestershire, as well as with some smaller specimens from Hallaig, in the 

 Isle of Skye, given to me by Professor Tate, and arrived at the conclusion that the 

 British examples agreed with those from Germany. 



I believe that several of the described German so-termed species should be united to 

 the one under description, but as I do not possess authentic types of some of them I should 

 not like to write out a list of the synonyms. It appears to me that Bh. ammonitica and 

 Bh. yryphitica of Quenstedt may perhaps be united to Bh. oxynoti, from their having 

 the rostral third of each valve smooth ; they could not be so well located with either Bh. 

 calcicosta or Bh. plicatissima . Professor Tate adds T. maceana, d'Orb. ('Prod.,' p. 221, 

 1850), Bh. Buchii, Chapuis et Dewalque (1854), and Bh. ranina, Suess (1860), to the 

 synonyms of Bh. oxynoti. 



215. Rhynchonella triplicata juvenis, Quenstedt. Dav., Ool. Mon., PI. XVI, figs- 



2 and 5 (not Bh. variabilis) ; and 

 Sup., PI. XXVIII, figs, 35, 36. 



Terebratula triplicata juvenis, Quenstedt. Handb., p. 451, pi. xxxvi, fig. 2, 1851. 

 — ■ — — Quenstedt. Der Jura, p. 74, pi. viii, figs. 16 — 23, 



1858. 



Shell small, subpentagonal, or oval, about as wide as long. Dorsal valve moderately 

 or greatly convex, smooth to about two thirds of its length, whence from four or nine 

 marginal ribs extend to the front and margin of the shell ; two or three of these ribs form 

 a short mesial fold. Ventral valve smooth, likewise, to within a short distance of the 

 margin, sinus moderately deep, beak incurved, foramen minute, proportions variable. 



