53G Mr. R. ^V. Hooley on the 



Group No. 3. 



Beaks -with strong lateral compression forming dorsal 

 keel, triangular in section, triincated tip, moderate vertical 

 depth. Dorsal outline rising from the tip at a high angle. 

 Longitudinal ridge on palate as in Orinthocheirus. Very 

 large circular teeth, anterior much larger than posterior, 

 none directed forward. 



Examples : — 



O. crassidms (Seeley). II. G. Seeley, ' Ornithosauria,' 1870, p. 122. 

 O. curyiinathm (Seeley). II. G. Seeley, ' Ornithosauria,' 1870, p. 123. 

 O. j)lafijsomus (Seeley), H. G. Seeley, ' Ornithosauria,' 1870, p. 120. 



To this genus we would give the name Amblydectes. 



Group No. 4. 



Massive truncated club-shaped snout, great vertical 

 depth, longitudinal ridge on palate, teeth subcircular and 

 vertically directed, front pair much smaller than the rest. 



Examples : — 



O. ca2^ito (Seeley). II. G. Seeley, ' Ornithosauvia,' ]870, p. 126. 



O. corteri (Seeley). II. G. Seeley, ' Ornithosauiia,' 1870, p. 128. 



0. 2}l(ityrhimis (Seeley). II. G. Seeley, 'Ornithosauria,' 1870, p. 128. 



O. shmis. R. Owen, Kep. Cret. Form. (18G1), Suppl. iii. pis. i. & ii., 



pi. iv. fig. 4. 

 O. woodivardi. 11. Owen, Rep. Cret. Form. (18C1), Suppl. iii. pi. ii. 



fig. 3. 



For this group it would be well to give the generic name 

 Ci-iorhynchin^, Criorhynchvs simus being the type. K. Ly- 

 dekker * suggested that if it "should prove generically 

 different from Ornithochcirus the name Criorhynchvs might 

 be retained for it." 11. Owen, in 1861 f and 1874 J, deter- 

 mined the type-specimen as belonj^ing to the upper jaw, and 

 S(cley in 1870 § remarked : ''a re-e.\amination of the type, 

 Plerodiictylun shiius, 0\^en, has convinced mc that it is a lower 

 jaw." Afterwards, however (1881) ||, he altered this view. 

 We have a certain character to denote the upper and lower 

 jaw in the presence of a longitudinal ridge on the palate on 

 the former and a groove on the latter. As the ridge is to be 



* II. Lydeltker, B. M, Cat. 1881), p. 3. 



t K. Owen, Hep. Cret. Form. (Men. I'al. Sue. 1801), Siippl. iii. p. 2. 



I Id. ibid. pt. i. (1874) p. G. 



$ II. G. Seoley, ' Ornithos'auria,' 1870, p. 127. 



II Id. Geol. Mag. [2] vol. viii. (1881) p. \'k 



