310 R. Lydekker — Hordwell and other Crocodilians. 



London Clay Crocodilians. — Having concluded what I have to say in 

 regard to Diplocynodon, I may mention that a comparison of the 

 type skulls of the so-called Crocodilus champsoides and C. toliapicus, 

 Owen, from the London Clay, has convinced me that these forms 

 are nothing more than young and old individuals of a single species,^ 

 for which we should therefore adopt the original name C. Spenceri, 

 Buckland.^ The so-called C. Arduini, Zigno,^ from the Nummulitics 

 of Verona, appears to be specifically indistinguishable from the 

 English form. 



The Wealden genus Hylcsochampsa. — In his sixth supplement to the 

 Eeptilia of the Wealden and Purbeck (Mon. Pal. Soc. 1873), p. 1, 

 Prof. Sir K. Owen applied the name of HylceocJiampsa to the imperfect 

 posterior part of the cranium of a small Crocodilian from the 

 Wealden of Brook, which was figured in pi. v. figs. 23-25 of the 

 preceding supplement of the same monograph. This specimen is 

 new in the British Museum (No. E. 177), and differs from all other 

 English Wealden Crocodilians by the extremely backward position 

 of the posterior nares, which are situated immediately in advance of 

 the pterygoids ; and by the supratemporal fossae being decidedly 

 inferior in size to the orbits. It is further characterized by the 

 orbits communicating freely with the lateral temporal fossae^ as iu 

 recent Crocodilia, instead of being completely shut ofi" from them as 

 in the Teleosauridce. Now the above features being those given by 

 M. DoUo* as characteristic of his so-called Bernissartia,^ the type of 

 the family BernissartiidcB, from the Wealden of Belgium, it becomes 

 necessary to consider in what respects that form differs from Hylceo- 

 cJiampsa. On page 322 of his memoir M. Dollo observes that 

 Bernissartia is distinguished from " Eylceochampsa par I'absence de 

 tout echancrure orbito-latero-temporale " ; but as this statement is 

 entirely erroneous,' the one point of distinction which he indicates is 

 invalid. As far, indeed, as I can see, the cranium of Hylcsochampsa 

 appears to agree exactly not only in form, but also in size with that 

 of Bernissartia, and I accordingly regard the two as specifically 

 identical ; in which opinion I have the support of my friend Mr. G. 

 A. Boulenger, who has been good enough to compare the type speci- 

 men with M. Dollo's description and figure.^ Under these circum- 

 stances the name Bernissartia Fagesi must apparently give way 

 to that of Hylcsochampsa Vectiana. The perfect preservation of 



^ Analogous modifications in a still more marked degree are exhibited in the three 

 crania of the existing long-nosed C. intermedins figured by Liitken in the ' ' Vidensk. 

 Meddell," 1884, p. 61, pi. v. 



' "Woodward, Geol. Mag. op. cit. p. 508. 



3 Mem. Ac. E. Lincei, ser. 3, vol. v. p. 67, pi. i. (1880). 



* The " echancrure orbito-latero-temporale " of Dollo. 



5 Bull. R. Hist. Nat. Belg. vol. ii. p. 334, pi. xii. (1883), 



« Ibid. p. 222. 



' M. Dollo's statement was probably derived from Sir R. Owen's figures, but fig. 

 24 shows most clearly the vertical bar occurring in the middle of this vacuity ; the 

 rims of the parieto-frontal and quadrato-jugal regions having been broken away. 



^ The onus of proving any distinction between Hylaochampsa and Bernissartia 

 now rests entirely with M. Dollo. 



