534 



MR. T. II. WITHERS ON 



Text-fie-. 65. 



Fig. 6. Scalpellum arcuatum Darwin. Nearlj' complete capitulum showing tlie 

 left side iippermostj with the valves somewhat displaced and broken. X 2 

 diam, Albi.in, Gault: Folkestone, Kent. Brit. Miis. (Nat. Hist.), 1. 13577. 

 c, carina, showing the inflected intraparietes j ^.1, outer portion of left 

 tergura ; t. %, inner view of right tergum near apex, showing the ridges 

 evidently connected with the firm attachment of the corium ; s. 1, outer 

 portion of left scutum ; s. 2, inner view of right soutum showing the pit 

 for the adductor scutoi'um ; I., upper latus ; r.l„ rostral latus with upper 

 portion broken off; r., rostrum. 



. Id. Outer view of incomplete rostral latus, "^ 



. Id, Inner view of same. | 



. Id. Outer view of rostrum. j- 5< 4 dignj. 



. Id. Hypothetical transverse section of same. 



. Id, Side view of game. 



Restored capitulum oi Scalpellum arcuatum Darwin. This figure is based 

 on the nearly complete capitulum represented by fig. 6, with the addition 

 of a cai'inal latus and an infra,median latus. These two yalves have not yet 

 been discovered in the Gault. X 2 diam, Albian, Gault : Folkestone, 

 Kent. O.I., carina! latus ; ?.?., infra-median latus. 

 Fig. 8, Scalpellum arcuatum Darwin. Two scales of the peduncle, a, outer view, 

 h, inner view ; c, outer view ; d, inner view. X 8 diam. Albian, GjiuJt ; 

 Folkestone, Kent. Brit, Mus. (Nat. Hist.), I, 13580, 



