xl INFERIOR OOLITE AMMONITES. 



11. Liockbas Thompsoni, S. Buckman. Suppl., Plate VII, figs. 13 — 16. 



Cf. ? 1818. Nautilus m^andeus, Eeinecke, pi. i, figs. 3, 4. 



Description. — Platyleptogyral, subgradumbilicate, flexiradiate — striate and 

 parvicostate. 



Distinction. — From partitum, thicker, more ornate, and concentrumbilicate ; 

 from bijidatum, less umbilicate, less costate, thicker. 



Remarks. — It is just possible that this species may be the Am. mseandrus 

 (Reinecke) ; but, considering how very inferior is that author's figure, it seems 

 preferable to definitely give this species a distinct name than to hazard a most 

 speculative identification. If Reinecke's specimens were in existence it would be 

 another matter, but they are not ; and the most diverse views have been expressed, 

 not only as to the identification of mseandrus, but as to what stratum it came 

 from. Thus Quenstedt says that the original locality, " Langheim, would indicate 

 the Omatus beds" 1 (Oxford clay); while Zieten figures as mseandrus 3 what 

 appears to be Oxynotoceras oxynotus, which would be from the Lias. Under these 

 circumstances it is advisable not to attempt any identification of Reinecke's 

 figure. 



Accordingly I name this species in compliment to Mr. Beeby Thompson, 

 F.Gr.S., who has done such good work among the Liassic rocks of Northampton- 

 shire. I am indebted to him for very kindly adding this and several other good 

 Ammonites to my collection. 



Localities and Strata. — Northamptonshire : Duston, near Northampton, in the 

 sands of that name. Dorset : Burton Bradstock, with the other species. 



Date of Existence. — Scissi hemera. 



C. Species which have reached the striate stage. 



12. Liooeras lineatum, 8. Buckman. Suppl., Plate VIII, figs. 1 — 3. 



Description. — Platyleptogyral, costati-gradumbilicate, flexistriate. 

 Note. — The remains of the costate stage may be seen in the bulgings visible in 

 the umbilicus. 



Distinction. — The umbilicus is more coarsely costate than in Thompsoni. 



1 ' Amm. Schwab. Jura,' p. 442. 



2 ' Verstein Wiirtt.,' pi. ix, fig. 6. 



