PLATE XXV. 



Fig. Fag's. 



1. Pachythrissops Jsevis, sp. nov. ; nearly complete fish, left lateral" view, 



nat. size, with part of operculum (1 a) enlarged six times to show 

 slime-pit. — Middle Purbeck Beds; Swanage, Dorset. The type 

 specimen. British Museum, no. 40433. br., branchiostegal rays ; 

 cl., clavicle; op., operculum; pop., preoperculum ; scl., supraclavicle ; 

 sop., suboperculum. 129. 



2. Ditto; left dentary, outer view, one-third nat. size. — Ibid. British 



Museum, no. 36083. 131. 



3. Ditto; vertebral centrum, end view to show perforation by notochord, 



nat. size. — Ibid. British Museum, no. 21974. 132. 



4. Pachythrissops vectensis, A. S. Woodward; imperfect fish, right lateral 



view, one-quarter nat. size. — Weald Clay ; Atherfield, Isle of Wight. 

 Collection of Reginald W. Hooley, Esq., F.G.S. a., portion of anal 

 fin; ag., angular; br., branchiostegal rays; cl., clavicle ; 'ry>/.,ecto- 

 pterygoid ; m/x., maxilla; pet., pectoral fins; plv., pelvic fins; qu., 

 quadrate; scl., supraclavicle; sy., symplectic; ,>•., probably post- 

 temporal. 133. 



5. Ditto; upper part of left hyomandibular, outer view, one-half nat. size. — 



Wealden ; Isle of Wight. British Museum, no. 42013. p., process 



for support of operculum. 134. 



