370 CARBONIFEROUS LAMELLIBRANCHIATA. 



Road, and I am permitted by the kindness of Dr. Henry Woodward to refigure it. 

 PI. XL, fig. 15. It unfortunately consists of only the anterior two-thirds of a 

 right valve ; the curious and characteristic posterior end is not seen beyond 

 the acute oblique line. I have a specimen, however, of the posterior two-tliirds 

 of the left valve, fig. 16, PI. XL, which therefore allows a complete description 

 of the exterior to be given at last. Curiously enough, in spite of the apparent 

 rarity of the shell, it has been re-described or catalogued by several authors, who 

 have all referred the shell to one or other genus of the family Arcidse, although 

 its very definite, concentric, external sculpture is not like that which obtains in 

 any member of that family ; nor are there the radiating lines which are possessed 

 by all striated species of the latter. The acute ridge, and hollowed, smooth 

 dorsal slope and concentric ribs are in complete accordance with characters 

 which I consider as diagnostic of the genus Sanguinolites. 



To Phillips's original description the following note is added : " The figure is 

 partly restored at the extremities." This should ve^d posterior extremity only, as 

 the anterior end of the type specimen is quite perfect. 



Whether or no the shells which de Koninck and de Verneuil referred to 

 Phillips's species really belonged to it, I am unable to say. The former professes 

 to have seen the anterior part of the hinge, but it is not figured. In de Koninck's 

 later work the shell is unrecognisable from the drawing; but it is stated that the 

 artist had not made the ribs strong enough. I cannot conceive that any artist 

 could have possibly had a specimen of 8. argutiis in his hands when he drew that 

 figure ; neither does de Koninck's description convey to my mind the characters 

 of Phillips's shell. It is as follows : " Une carene bien prononcee traverse 

 diagonalement sa surface qui en outre est garnie de nombreuses stries concen- 

 triques assez regulieres et quelques fois assez profondes." Writing of the 

 umbones, he states, " lis sont tres rapproches et separes par une facette 

 ligamentaire tres etroit et presque lineaire." As to the hinge, the same partial 

 description is given as in his earlier work. From the whole description I 

 consider it extremely doubtful whether 8. argutus really occurs in Belgium, and 

 think that a totally different shell has been described under this name, which, if 

 de Koninck really saw, as he states, the anterior portion of the hinge, evidently 

 belongs to Paralhlodon. Whether Julien and Tornquist have Phillips's or de 

 Koninck's shell from the Carboniferous beds of Central France and Alsace, I am 

 unable to say. 



I have not met with any specimens of this species in the Carboniferous 



beds of Scotland, and suspect that some other shell must have been erroneously 



identified as 8. argutus by the authors of the Scottish catalogues referred to above. 



This species resembles 8. angustatvs more nearly than any other, but can at 



once be diSerentiated by the following characters : — Less transverse, more 



