xlii INFERIOR OOLITE AMMONITES. 



15. Lioceras striatum, S. Buckman. Plate XIII, figs. 6, 12; Suppl., Plate X, 



fig. 10. 



1884. Harpoceras opalinum, Wright, Monogr. Lias Amm,, Pal. Soc, pi. lxxx, 



fig. 4 (?). 

 1888. Lioceras opalinum, This Monogr., PI. xiii, fig. 6. 

 1888. Lioceras between opalinum and comptum, PI. xiii, fig. 12. 



Description. — Platyleptogyral, gradumbilicate, flexistriate. 



Distinction. — Like opalinum, but with a wider umbilicus. The peripheral area 

 is a little less acutely fastigate. There is a similar fasciation to what obtains in 

 opalinum, but it is scarcely noticeable in the young shell, which appears simply 

 striate. This appearance distinguishes it from other gradumbilicate species, 

 which are costate in the umbilicus — for instance, undulatum, which it resembles 

 in its proportions. 



Remarks. — From the figure only I cannot say if Dr. Wright's specimen belongs 

 to this species, or even to this genus ; but it agrees in proportions : all depends on 

 the radial line. 



Localities and Strata. — Dorset : Burton Bradstoek, with the other species. 

 Gloucestershire : Penn Wood, near Stroud (sandy ferruginous limestone) ; Frocester 

 Hill. 



Date of Existence. — Scissi hemera. 



16. Lioceras sp. Plate XIV, figs. 1,2; Suppl., Plate X, fig. 9. 



1888. Lioceras opalinum, var. comptum, This Monogr., PL xiv, figs. 1, 2. 



Distinction. — From opalinum, by being thicker and having a smaller umbilicus 

 with the excentricity commencing earlier. From grave, by a smaller umbilicus. 

 Locality and Stratum. — Dorset : Burton Bradstoek, with the other species. 

 Date of Existence. — Scissi hemera. 



D. Species which have reached the renovate stage. 



Distinguished from all other species of the genus by the ornament increasing 

 instead of decreasing with growth — a costate stage succeeding a striate stage. 



