82 VERTEBRATA, 



actually manufactured up into coat buttons in considerable 

 numbers (!). 



Localities. Upware, Brickhill, Potton, Shanklin (I. W.), Far- 

 ringdon (Berks.). 

 S. Europe. Dept. de l'Aube, Alais, Auxerre, Landeron, 

 Neuchatel, St Croix. 



Strophodus, sp. 



Strophodus reticulatus, Agassiz ? 



Psammodus reticulatus, Walker, Geol. Mag. Vol. IV. p. 310 (see 



Psammodus reticulatus, Ag. Poissons 

 i^ss.VoLin.p. 123, pi. 17, 1. From the 

 clay at Shotover (Kimmeridge clay). 



This species is undistinguishable from the Strophodus reti- 

 culatus, Ag. of Shotover, and also from the S. subreticulatus, Ag. of 

 Soleure, according to MM. Pictet and Campiche. Still there can 

 be little doubt that when better specimens are found to shew the 

 arrangement of the teeth in the jaws we shall find evidence of the 

 specific distinction of the Neocomian and Kimmeridgian species, 

 and the former might then very appropriately celebrate the great 

 Palaeontologist who first described it by bearing the name Stro- 

 phodus Picteti. 



Localities. Upware, Brickhill, Potton. 

 S. Europe. St Croix, Switzerland. 



Pycnodus Couloxi, Agassiz. 

 (Plate I. fig. 5, a, b.) 



Pycnodus Couloni, Ag. 1843. Poissons Fossiles, II. pt. 2, p. 200. 

 „ „ Pictet and Campiche, Terr. Cret. St Croix, 



p. 57, pi. 7, fig. 5—17. 

 „ „ de Loriol et Gillieron, Pal. Landeron, pi. 1, 



5—7. 

 Pycnodus gigas, Walker, Geol. Mag. Vol. iv. p. 310 [and Pal. 

 Soc. in Lycett]. 



With this species there exist difficulties just similar to those 

 we meet with in the Sphaerodus teeth. Agassiz writes : " Elles 



