PYCN0D0NTID2E. 
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Type. Mandibular dentition. 
A large species known only by the dentition, of which the splenial 
is indistinguishable from that of G. circularis. Yomer with pro¬ 
minent mammillated median teeth, usually not quite equalling the 
two flanking series in width, and scarcely more elevated than the 
outermost of the latter, which comprises triangular teeth rising to a 
conical apex; inner flanking teeth relatively small, low, rounded, 
and highly ornamented. 
The form and degree of ornamentation of the principal teeth on 
the splenial in this species vary considerably. The immature and 
smaller specimens are named G. orncitissimus by Blake. 
Form. Sf Loc. Lower Kimmeridgian: Dorsetshire, Wiltshire, and 
Cambridgeshire; K. Trance. 
P. 7456. Fine example of the vomerine dentition, 0*035 in 
maximum width ; Kimmeridge Clay, Poulshot, Wiltshire. 
41868, 43026, 43561, 43563, 44085. Five small vomers, the two 
first comparatively narrow and with very prominent 
median teeth; Kimmeridge Clay, Weymouth. 
Purchased , 1869, -71, -72, -73. 
P. 1615, P. 3785. Three similar specimens ; W'eymouth. 
Egerton and Enniskillen Colls. 
P. 6151, P. 6166. Four similar specimens, one being figured by 
Damon, op. cit. pi. xi. fig. 4 ; Weymouth. These and the 
splenials numbered P. 6168 may be regarded as the type 
specimens of the so-called Gyrodus oimatissimus. 
Damon Coll. 
P. 1618. Plaster cast of large right splenial; Kimmeridge Clay, 
Boulogne. Egerton Coll. 
32746. Somewhat smaller left splenial; Kimmeridge Clay, Ely. 
Purchased , 1857. 
38553. Imperfect smaller specimen, probably from Ely. 
Purchased , 1864 
43025. Fine left splenial of moderate size; Kimmeridge Clay, 
Weymouth. Purchased , 1871. 
41227, 41963. Portions of right and left splenials, with remarkably 
smooth principal teeth, and the first specimen exhibiting 
a supplementary row of small teeth within the outermost 
series; Weymouth. Purchased, 1868,-70. 
pakt hi. 
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