SUPPLEMENT.— LTOCERAS. xxxvii 



yellow sands) ; Stoke Knap (sandy grits, about the horizon of Terebratula infra- 



oolithica and Bhynchonella Stephensi). 

 Date of Existence. — Scissi heraera. 



2. Lioceras uncdm, 8. Buchnan. Suppl., Plate VI, figs. 8 — 10. 



Platyleptogyral, gradumbilicate, flexi-subparvicostate. 



Distinction. — From uncinatum, less costate and less umbilicate. 



Note. — The costaa are by no means so strongly marked as in uncinatum, and 

 they show signs of degeneration when those of that species are well developed. 



Locality and Stratum. — Burton Bradstock (in the grey limestone above the 

 yellow sands). 



Date of Existence. — Scissi hemera. 



3. Lioceras costosqm (Quenstedt). Suppl., Plate VI, figs. 1 — 4. 



188(5. Ammonites opalintts costosus, Quenstedt, Aniin. Schwab. Jura, pi. lv, 



fig. 20. 



Description. — Platyleptogyral, gradumbilicate, flexi-subparvicostate. 



Distinction. — From uncinatum, less umbilicate; from rincum, umbilicus is 

 slightly larger and less sparsicostate. 



Note. — The costse visible in the umbilicus are closer together and not so large 

 as those of uncum. 



Localities and Strata. — Dorset : Burton Bradstock, in grey limestone above 

 the sands ; Symondsbury, in yellowish-grey limestone with Tmetoc. scissum, below 

 Zeilleria anglica and Amm. of the Murchisonse type. 



Date of Existence. — Scissi hemera. 



4. Lioceras subcostosum, S. Buclcman. Plate XX, figs. 11, 12 ; Suppl., Plate VI, 



figs. 5—7. 



1889. Lubwlgia costosa, This Monogr., Pi. xx, figs. 11, 12. 



Description. — Platyleptogyral, subgradumbilicate, flexi-subparvicostate, peri- 

 pherally subacutifastigate. 



Distinction. — From costosum, less umbilicate and more compressed. 



