AN AUSTRALIAN SATTROPTERYGIAN — ETHERIDGE. 27 



Amongst the numerous fragments of ribs are several that seem 

 to be the proximal ends of trunk ribs (PI. vii., Figs. 5 and 6), but 

 if so the terminal faces are cupped for the reception of the convex 

 heads of the d {apophyses already described. None are absolutely 

 perfect, but the figures given will explain their appearance and 

 characters almost better than words. However, the head of the 

 rib is in each case expanded and terminally hollowed into an 

 oval rather deep depression or cup of variable size. This appears 

 to be similar to the structure described by Hector in Lieodon 

 haumuriensis* 



The proximal ends of both humeri (PI. vii., Fig. 1) are present in 

 the collection, and very remarkable bones they are, allied in many 

 respects to those of Mauisaurus haastii, Hector, f One is three 

 inches long, the other three and a quarter inches approximately. 

 They are heavy and much thickened bones, the proximal articular 

 surface hemispheric, with a sharp angular periphery and a dia- 

 meter of about one and three-quarter inches. The trochanterian 

 process is much thickened, and protuberant, and separated from 

 the articular surface by a well marked although incomplete bici- 

 pital groove, overhung by sharp margins. The transverse diameter 

 of the humeri is one and a half inches. The distal sloping surfaces 

 of the bones are much roughened and pitted for muscular attach- 

 ment. To one side of the trochanterian process in each is what 

 Dr. Hector calls in Mauisaurus a bold rugose tuberosity '* to 

 receive the attachment of the bicipital tendon."| The plantar 

 surfaces would appear to be somewhat concave. 



These humeri seem to possess some important points of depar- 

 ture from the ordinary Plesiosaurian humerus, but are closely 

 allied in form and character to those of Mauisaurus, at the same 

 time showing sufficient differences of a distinguishing nature. 

 For instance we see the very marked trochanterian process well 

 separated from the articular surface, or head of the bone, by the 

 bicipital groove, although not circumscribed by it, as such appears 

 to be the case in M. hastii. We further see an equally large, 

 although less hemispheric articular surface, and an equally strong 

 if not stronger protuberance for the bicipital tendon, whilst the 

 latter is somewhat differently placed to what it is in the New 

 Zealand reptile. 



Two short, transversely elongated bones are distinguishable 

 that may be one or other of the paddle-bones, possibly the " inter- 

 medium." (PI. vi.. Fig. 6). The terminal faces are roughly 

 facetted. 



» Trans. N.Z. Inst., vi., 1874, p. 352. 

 t Ibid, p. 347. 

 X Loc. cit., p. 348. 



