424, Professor H. L. Hawkins— 
each column consisting of an almost median primordial row placed 
towards the adoral margins of the plates (except near the apex), 
continuous from apex to peristome, relatively small just below 
ambitus, and there accompanied by occasional orad supernumeraries. 
Radiad and interradiad rows introduced with some regularity 
(after about the third plate from peristome or apex), alternately 
near the apicad and orad margins of the plates, forming fairly 
regular transverse rows, the primordial tubercles entering the orad 
row of each plate. Five tubercles on each side of the median one 
is the rule for ambital plates, but occasionally more occur by develop 
ment of three in place of the normal two in the oblique series. 
Tuberculation (Pl. VII, Figs. 6 and 7), consisting of primary and 
secondary tubercles, and granules that sometimes appear almost 
tertiary tubercles. Primary tubercles with convex bosses and small 
perforate mamelons; areole always deep, but most noticeable 
adorally, where (from the ambitus) they become relatively large, 
occupying the greater part of the test-surface. Adapically the 
primary tubercles are comparatively small (much more so than in 
most species of Conulus or Pyrina) and rendered the less conspicuous 
by the strong development of secondaries. Secondary tubercles 
very numerous on adapical surface, with marked though shallow 
areole, giving a shagreen-effect above the level of the primaries. 
Scrobicular grouping around primaries not evident. Intervening 
space packed with granules (which may occasionally possess areole), 
adding to the extreme roughness of the adapical surface. No certain 
evidence of “sunken” or glassy tubercles, though in places 
impression of sand-grains gives suggestion of existence of the former. 
The only specimen at present known was collected from the 
‘“ Limestone Lenticles”’ at Shenley Hill, near Leighton Buzzard, 
Bedfordshire. The horizon of these lenticles is a matter of con- 
troversy, but the paleontological evidence points fairly conclusively 
to their Cenomanian age—perhaps correlating them with the sub- 
zone of Catopygus columbarius at the base of the zone of Schlenbachia 
varians. (The alternative reading of the section would locate the 
horizon in or about the Lower Gault.) 
Discussion of Affinities. 
In the preliminary note (Grou. Mac., Vol. LVIII, 1921, p. 58) 
I drew attention to the marked resemblance of the specimen to an 
Holectypus with marginal periproct, mentioning the Lower Oolitic 
species H. hemisphericus in particular. The appropriateness of this 
comparison will be obvious to anyone who handles the specimen ; 
but there are few features of real importance in which it is worth 
emphasizing. In essentials C. anomala is emphatically not one of the 
Holectypide, for it has no fifth genital, and its interradia! tubercula- 
tion is double on each side of the median row; whereas in Holectypus 
there is always a fifth genital, perforate in Cretaceous types (Coen- 
holectypus), and the interradiad tubercle-series form single transverse 
