from the Middle Purbeck of Swanage. 40.'^ 



but bis account of the palatal surface is obscure. The most 

 remarkable point about the palate (text-Hg. 2) is that the 

 pfeiyf2;oids {pt.) meet biMicath the ivisal passage and carry 

 back the internal naiial openino {i.nar.) exactly as in modern 

 crocodiles ; the median Eustachian 0|)ening {eri.vi.) is only 

 separated from the nares by a ridge of bone, probably mainly 

 formed by the basisphenoid. The palatal (suborbital) vacuities 

 {s.o.v.) are very narrow and are separated, as usual, by the nasal 

 tube formed by the palatines. Externally to these openings 

 the palate is perforated by another pair of vacuities {for.), 

 not seen in other crocodiles. They are large oval apertures, 

 which Owen was inclined to take for the true suborbital 

 vacuities, regarding the median pair as the internal nares. 

 This, however, is clearly not the case, the nares {i.nar.), as 

 already noted, being situate as in the Eusuchia. It becomes 

 necessary, therefore, to account for the outer pair of openings, 

 and a careful examination of the specimen shows that they 

 are the result of the bifurcation of the outer portion of the 

 very large transverse bone {t.p.), the posterior branch running 

 outwards and forwards to join the jugal, the anterior nearly 

 directly forwards to the maxilla (ina:.) ; the opening included 

 between the branches of the transverse line was no doubt 

 closed externally by the union of the maxilla and jugal, but 

 the specimen is unfortunately incomplete at tiiis point. This 

 opening has not been observed in any other crocodile; but it 

 is significant that in the transverse bone of all modern forms 

 there is, about opposite the point of union of the maxilla and 

 jugal, a small foramen, which completely perforates the bone 

 and is probably not a nutritive opening. It may be suggested 

 that this small opening is a remnant of the vacuity now 

 described on H y^ceochampsa, 



Anotiier remarkable point about the skull is that the series 

 of dental alveoli, of which two or three are preserved in eacli 

 maxilla, converge very rapidly towards one another in front, 

 as if the skull were very short ; but from the large size of the 

 nasals, so far as preserved, and from the peculiar pinching-iu 

 of the skull in front of the orbits, it seems more probable 

 that this convergence of the alveolar borders is merely a rapid 

 narrowing to pass into a slender rostrum of unknown length. 

 Of the remainder of the skeleton nothing is definitely 

 known ; but it is very probable that a series of procoolous 

 Crocodilian vertebraj described by Seeley (Quart. Journ. 

 Geol. Soc. xliii. (1887) p. 212, pi, xii. figs. 7-8), under the 

 name Ueterosuc/ius valdensis, actually belong to IJykto- 

 c/iatnpsa. If this is so, it adds another striking feature of 

 resemblance to the Eusuch'a. 



Ami. cD Ma(j. X. Hist. Ser. 8. Vol. xi. 34 



