SPIRIFERINA. 17 



/era, from which it may be hereafter removed, should the study of its interior demon- 

 strate the necessity. Mr. Morris has combined Martinia Winchiana, King, with 

 M. Clannyana} a view likewise adopted both by Baron Schauroth and Mr. Hovvse, and in 

 which I should also feel inclined to concur. Professor King, however, still insists upon 

 the separation, but the distinctions proffered do not appear to me to have been satisfactorily 

 made out, and seem more individual than specific. 



Loc. Sp. Clannyana has been collected rather abundantly at Ryhope-field House. 

 One example was also found at Tunstall-hill by Mr. Kirkby, and another from Pallion 

 may be seen in the Sunderland Museum. Professor King names Whitley as the locality 

 whence he obtained his Sp. Winchiana. German examples have also been discovered at 

 Possneck by Baron Schauroth. 



Sub- Genus — Spiriferjn a, D' Orbiyny. 



(Introduction, Vol. I, p. 82, 1853.) 



Spiriferina cristata, Schlotheim, sp. Plate I, figs. 37 — 40, 45, 46 ; Plate II, figs. 



43 — 45. (King's Monog., pi. viii, figs. 9 — 14.) 



Tebebbatulites cristata, Schlotheim. Beitr. z. Naturg. d. verst in Akademie der 



Wissenschaften zu Miinchen, tab. i, fig. 3, 1816. 



This variable shell is more or less transversely semicircular, moderately convex or 

 inflated ; the hinge-line as wide or slightly shorter than the greatest width of the shell. 

 The cardinal angles are more often rounded (PI. I, fig. 40), rarely prolonged with acute 

 terminations (PI. II, fig. 43). Area large, triangular, flat, or slightly concave, and placed 

 at almost right angles to the plane of the smaller valve, so that the beak is not often seen 

 to protrude to any extent beyond or above its termination. The fissure is rather wide, 

 triangular, and partially covered by a pseudo-del tidium. The number of ribs which 

 ornament the shell varies considerably, both according to age and individual ; the central 

 one in the dorsal valve (which represents the mesial fold) is, in general, twice as wide as 

 those which cover the lateral portions of the valve ; its crest is angular throughout, or 

 more or less flattened, especially towards the front. In profile it presents a regularly 

 convex curve, but in some individuals is slightly bent upwards near the front. In the 

 ventral valve the sinus is more often deep and angular, but is also sometimes flattened 

 along its centre. From four to fourteen angular or rounded ribs, of greater or lesser 

 width and depth, ornament each valve. When quite young, with dimensions not exceed- 

 ing one to one and a half line in length, and about the same, or a trifle more, in width 



1 ' Catalogue of British Fossils,' 2d edition, 1854. 



