160 SUPPLEMENT TO THE BRITISH 



evident from the inspection of these specimens, as well as of those obtained near 

 Banbury, that the indentation is not always present, or is at least an inconstant 

 character. This fact is referred to by the Rev. F. Smithe in his important and instruc- 

 tive ' Memoir on the Middle Lias or Am. spinatus Zone of the north of Gloucestershire,' 

 August 1877. 1 W. indentata occurs in Great Britain commonly at the top of the 

 Middle Lias, and is found in a similar position in a great number of French localities, 

 such as at Vieux Pont, Evrecy, and Fontaine-Etoupe-Four, Fontaine-le-Pesnel, &c, 

 near Caen. It is also, according to Mr. Deslongchamps, a common fossil in the 

 neighbourhood of Falaise, at Villy, Fresnay-la-Mere, and especially near Argentan 

 (Orne). 



This author refers Brocchi's Anomia biplicata (' Conchologia fossile Subapennina,' 

 p. 469, pi. x, fig. 8, 1814) to the species under description; but, as some uncertainty 

 still prevails with reference to the identification, he proposes that Sowerby's name 

 indentata should be retained for the Liassic species, and T. biplicata, Sow., for the 

 Cretaceous one — a view with which I entirely concur. He likewise states that part of 

 Alcide d'Orbigny's Ter. Sarthacensis probably belongs to W. indentata, while the other 

 portion constitutes a distinct species, which he describes as T. Sarthacensis, d'Orb., at 

 p. 130 of his ' Brachiopodes Jurassiques.' 



There can exist no doubt as to W. indentata being a true Waldkeimia, as, in addition 

 to its outward characteristics, Mr. Beesley has found a specimen showing the long loop 

 peculiar to that genus (PI. XXI, fig. 15). 



Sowerby describes his species in the following manner : 



" Elliptical, smooth, more or less gibbous ; valves equally convex, front deeply 

 notched, beak small, much incurved. In the young state this Terebratula, like others, 

 shows but slight signs of a marginal notch; when full grown the notch is deep and 

 obtuse angular ; broad furrows extend from at about one third the length of each valve ; 

 its length is nearly twice its breadth. Found abundantly in dark greenish-grey lime- 

 stone at Banbury and several other places. The two sides are not always equal." Sup., 

 PI. XXI, fig. 10, is from a drawing made from Sowerby's original specimen now in the 

 British Museum. 



1 The Rev. F. Smithe observes that " the evidence afforded by the palaeontology of the Am. spinatus 

 zone (in north Gloucestershire and elsewhere) strongly bears out the statement that we here possess an 

 example of an old sea-bottom of the mid-liassic epoch ; and, also, that we are justified in assigning to it a 

 definite position in the scale of depth. It formed a shelving shore of the division named by Professor 

 Forbes the Laminarian zone, which would be about fifteen fathoms deep from the sea level. This position 

 is shown by two distinct but associated groups of fossils. The first class of fossils would be the marine 



vegetation They are the stems and other remains of Algae of the olive group, which embraces 



the great sea-tangles. The stems are, where preserved, coriaceous in substance, showing no mid-rib, and 

 only a blurred outline of organs of fructification. These particulars harmonise with my first account, and 

 the evidence of them taken together is amply sufficient to lead us to place the depth of the spinatus beds 

 in the Laminarian division of the liassic shore." 



