244 
ACTINOPTERYGII. 
41392, 41870-73. Four fragments and one small much-worn vomer; 
Weymouth. Purchased , 1869. 
P. 3787. Portion of large vomer with much-worn teeth ; Kim- 
meridge Clay, Ely. Enniskillen Coll. 
32549. Dentition of large left splenial; Kimmeridge Clay, Havre. 
Tesson Coll. 
41391, 44088. Two examples of the left splenial; Weymouth. 
Purchased , 1869, 1873. 
P. 1614 a. Two right splenials; Weymouth. Egerton Coll. 
P. 3786 C. Eight and left splenials with very irregular principal 
teeth, and the former showing a supplementary inner 
series of minute teeth; Weymouth. Enniskillen Coll. 
Gyrodus planidens, sp. nov. 
1880. Gyrodus ornatissimus, E. Damon, Geol. Weymouth, ed. 2, Suppl. 
pi. xi. fig. 6 {errore). 
Type. Yomer; British Museum. 
A species of moderate or small size, known only by the vomer, 
which bears highly ornamented and widely spaced teeth. Teeth 
of median series on the vomer much less in width than the two 
flanking series, neither the median nor the outermost teeth much 
more elevated than those of the inner flanking series, which are, 
however, the smallest. 
The splenial dentition of this species is either unknown or indis¬ 
tinguishable from that of G. cuvieri. 
Form. Sf Loc. Kimmeridgian : Dorsetshire. 
P. 6166 a. Type specimen figured by Damon, loc. cit .; Kimmeridge 
Clay, Weymouth. 
44086. Yomer : Wevmouth. 
/ » 
P. 3785 b. Another fine vomer ; Weymouth. 
P. 1615 a. Imperfect vomer; Weymouth. 
41393. Two small specimens ; Weymouth. 
Damon Coll. 
Purchased , 1873. 
Enniskillen Coll. 
Egerton Coll. 
Purchased, 1869. 
Gyrodus murchisoni, Mantell. 
1844. Gyrodus murchisoni , G. A. Mantell, Medals of Creation, p. 643, 
fig. 134. 
Type. Portion of vomer; British Museum. 
A large species known onl}- by the vomerine dentition. Teeth of 
