T. Davidson — Tertiary Brachiopoda. 401 



mens of this species. The surface is ornamented by numerous radiating 

 ribs, with interspaces between them of about equal breadth. In these 

 intersj)aces are interpolated one or two shorter ribs, the entire surface 

 being crossed at intervals by concentric lines of growth. This shell 

 has been confounded by Baron Schauroth and others with the Tere- 

 hratuUna tenuistriata of Leymerie, but in this last named shell the 

 ribs are much finer and more numerous than in the species under 

 description. T. striatula (if I am correct in my identification) was 

 found by Sig. Meneghini, at Breonio, and by Mr. Bayan, in his 

 Eocene stages, E. and F., at the Bucca di Scissa and Val di Scaranto, 

 near Brendola (Colli Berici) ; Castellunga near Castelcies ; Lonigo, 

 and Val di Lonte in the Vicentin ; Valle Organa near Bassano ; as 

 well as in his Oligocene, stage G-., at San Gonini Lugo. 



28. Terebratulina ? WicJielotfina (Dav.), PL XIX., Fig. 22, 22a. 



Shell small, oval, compressed, longer than wide, broadest ante- 

 riorly, sides and front rounded ; hinge-line straight, a little less than 

 the width of the shell ; beak prominent, area flat, fissure large and 

 laterally margined by prominent deltidial plates; dorsal valve semi- 

 circular, elongated, with acute cardinal extremities, very slightly 

 convex ; surface of valves ornamented with from 22 to 24 radiating 

 rounded ribs, of which half that number commence at variable 

 distances from the beaks and extend to the front, so that a smaller 

 or shorter rib intervenes between each pair of the larger ones. The 

 shell is largely punctured ; interior not known ; length 4, width 3, 

 depth 1 line. 



Mr. Bayan collected three or four examples of this pretty little 

 shell in the Eocene, stage E., at Mossano (Colli Berici) near Vicenza. 

 It is remarkable on account of its flattened appearance, as well as 

 from the length of its hinge-line. 



29. Terehratula (or Waldheimia ?) Hilarionis (Meneghini M.S.) PL 

 XYII. Fig. 4, 5. Terehratula Milarionis (Meneg. ) Bayan, Bull ; Soc. 

 Geol. de France, second series, vol. xxvii., p. 459. 1870. 



Shell variable in shape, nearly circular, a little longer than wide, 

 broadest posteriorly, tapering gradually towards the front wliich is 

 more or less regularly rounded. Dorsal valve either moderately 

 and uniformly convex or with a slight median depression in the 

 anterior half of the valve. Ventral valve convex and slightly deeper 

 than the opposite one ; beak small, rounded, and much incurved — 

 laterally compressed and keeled along the middle ; beak ridges sharply 

 defined, foramen minute ; surface of valves smooth ; length 15, 

 breadth 14, depth 8 lines. 



The identification of this shell has given me some trouble, and I 

 am still uncertain whether it might not be referable to a species 

 already named. It bears a striking likeness to some forms of Liassic 

 Waldheimia numismalis, and it is possibly the shell alluded to by 

 D'Archiac in the third volume (p. 276, 1850) of his " Histoire des 

 Progres de la Geologic," under the designation of T. subnumismalis ; 

 this species being stated to occur in the Eocene beds of the Kressen- 

 berg, but as the Viscount neither describes nor illustrates his species 

 his name cannot supersede the same designation given by myself to 



