Figs. 1, 
Fig. 3. 
Fig. 4. 
[PLATE VII. Prare 18.] 
SECTION 2.—PTERYGOTUS. 
Pterygotus anglicus. TECTOGNATHS AND ENDOGNATHS. 
2. The basal joints or coxognathites of the two large swimming feet (or ectognaths). 
At ¢is the notch for the attachment of the other joints. The pair are probably 
not placed quite in the natural position, as their expanded bases should be nearer 
together (after the manner of those in Plate I. fig. 4.) Fig. 1 is of the natural size, 
and Fig. 2 is reduced to two-thirds its size, to correspond withit. (Lord Kinnaird’s 
cabinet. ) 
The end of the serrated process of a large specimen of the same part, which has 
already been figured by Prof. Agassiz. (Watt Institution. ) 
The (right?) endognath, with its long palpus; , the produced outer angle of the 
basal joint. The terminal joint of the palp g, represented in Prof. Agassiz’s figure, 
is wanting in this specimen. (Lord Kinnaird’s cabinet.) 
An endognath of the opposite side, with the three first joints of its palpus. (Watt 
Institution. ) 
. The second and third joints of a large palpus. (Lord Kinnaird’s cabinet.) 
The basal joint of a much elongated endognath. The region on the inner side of the 
palpus is much longer than in those represented in Figures 4 and 5, and it probably 
belongs to a different pair, pp. 187, 248. (Watt Institution.) 
