Devomai,.-\ PALEONTOLOGY OF VICTORIA. ^Animals. 



ridges after branching which so often gives the semii'adiate character 

 to the surface of that species, and they are much finer and more 

 numerous, being in this species 13 in 3 Hues at 3 Hnes from the 

 beak, but only aljout 7 in same space at same part of C. sarcinulata. 

 Very abundant in the Middle Devonian limestone of Lucknow, 

 E. of Mitchell River ; also of Buchan. 



Explanation of Figures. 



Plate XXXV. — Fig. 3, magnified view of half of larger valve, showing the branching ridges 

 and the tubular spines on the hinge-line. Fig. 4, magnified, half of smaller valve, showing the 

 more simple ridges. Fig. 5, portion of limestone, showing the largest specimen seen, natural 

 size, with others of the more ordinary dimensions, showing the gregarious nature of the species. 



Plate XXXV., Figs. Q-Gb. 

 PHRAGMOCERAS SUBTRIGONUM (McCoy). 



[Genus PHRAGMOCERAS (Brod.). (Sub-kingd. Mollusca. Class Cephalopoda. Order 

 Tentaculifera. Fam. Nautilidse. 



Gen. Char. — Shell short, arched, compressed ; septa simple, crossed by sigmoidal lines of 

 growth ; siphon at the inner edge, dilated between the septa.] 



Description. — Gradually tapering-, gently arched ; section subtrigonal ; peri- 

 phery broadly convex ; sides flattened, converging- to a narrow convex inner side ; 

 siphon large (;iboiit Si lines long, and 3 lines wide at ninth septum from last), oval, 

 about half its length from inner edge ; septa moderately convex with a slight forward 

 wave at inner edge. Surface with sub-equal obtuse longitudinal ridges, sej>arated 

 by hollows about their own width, about 5 ridges in half an inch near last chamber. 

 The last 9 septa occupy 1 inch on the inner side, and 1 inch 7 lines on the outer 

 side, the outer distance apart being little greater than the inner for the latter 

 chambers, but nearly double of it for the preceding chambers, where the general 

 curvature is greater ; antero-posterior diameter at last chamber 2 inches 4 lines (1 inch 

 9 lines at 9 septa back) ; greatest transverse diameter near middle nearly the same 

 as the antero-posterior. 



The genus Phragmoceras is only found in Lower and Middle 

 Palaeozoic rocks, not continuing to the Carboniferous period, and the 

 present S23ecies belongs to the less compressed group found in the 

 Devonian formations. This sjiecies is easily distinguished by the 

 near equality of the two diameters of the septa and the subtrigonal 

 form of section resulting fi-om the convergence of the flattened 



[ 18 ] 



