Victorian Fossils, Part XIX. 99 



Diaphorostoma incisum, sp. nov. (Plate V., Fig. 46 ; Plate VI., 

 Fig. 59). 



Description. — Shell dejiressed, helicoid; spire moderately de- 

 pressed, rapidly widening to body whorl, of four volutions. Penul- 

 timate whorl one-third the diameter of the body whorl. Surface 

 of shell gently convex, marked with numerous closely set, incised 

 growth-lines, which are sometimes undulate and crossed by sparse, 

 radiating folds. Aperture large^ subovate. 



Ditnensions. — Extreme width, circ. 40 mm. Height, 18 nun. 



Observations — In general character the above species approaches 

 D. lineatum, J. Hall sp., the fossil cited in the comparison of £>. retro- 

 7'ugatum, but in that species the body whorl does not increase so 

 rapidly in width, and the shell is higher. • The concentric orna- 

 ment also, whilst agreeing in its incised character, is not crossed 

 by so regular a system of radial lines. 



Whidborne's " Capidiis ? invicftis '''^ from the Middle Devonian 

 of Devonshire, is almost identical in form- with the Victorian 

 species, but the apical spire is smaller or more closely coiled. 



Occurrence. — Silurian (Yeringian). In dark limestone, Thomson 

 River, Gippsland. Collected by tlie Dept. of Mines, Victoria. No. 

 .91F. 



Fam. ? SiPHONARIIDAE, 



Genus Hercynella, Kayser, 1878. 

 Hercynella victoriae, sp. nov. (Plate V., Figs. 47, 48). 



Description. — Shell patelliform, depressed conical, with a sharp 

 apex. Slopes of shell alternately convexly and concavely folded; 

 one side, on the longer axis, is pinched up to form a subangulate 

 ridge extending to the apex. Concentiic lines of groAvth appearing 

 as low folds. Surface of shell radiately marked with close, low 

 riblets, strengthening as they appi'oach the ventral margin. 



Dijnensions. — Greatest length of holotype, 53 mm. Greatest 

 width, 35 mm. Approximate length, complete, 55 mm. ; width, 

 39 mm. Height 13.5 mm. 



Observations. — This interesting species resembles H. radians, 

 Barrande sp.2 in the radial ornament, but is more elongate-ovate 

 in* outline, and the vellication or pinching up of the dorsum is more 



1 Pal. Soc. Mon., vol. xliv., 1S91. Mon. Dev. Fauna S. of England, p. 204, pi. xix., figs. 1-2-14. 



2 Barrande's Syst. Sil. Boheme. Perner, vol. iv., tome i., 1903, pi. .xliii., figs. -20, 21 ; pi. xlviii., 

 figs. 16-24. Tome ii., 1907, pi. cxxi., figs. 15-18. 



Sa 



