382 Obituary — Sir William Edmond Logan. 



3. " On the Axis of a Dinosaur from the Wealden of Brook, in 

 the Isle of Wight ; probably referable to Iguanodon." By Prof. 

 H. G. Seeley, F.L.S., F.G.S. 



This perfect specimen, preserved in the Woodwardian Museum of 

 the University of Cambridge, is 3^ inches long and 3J inches high. 

 The odontoid process is anchylosed to the axis, and projects forward 

 as in the axis of birds, so as to articulate with the occipital condyle 

 of the skull. The pre- and postzygapophyses are situated much as 

 in birds ; as are the two ovate pedicles, on the anterior part of the 

 side of the vertebra to which the cervical rib was articulated. But 

 posteriorly the articular surface for the third cervical vertebra is 

 transversely ovate and slightly concave. The neural spine is com- 

 pressed from side to side, more so in front than behind. Among 

 mammals, the nearest resemblance to this kind of axis is seen simi- 

 larly in the whale ; and among reptiles the crocodile has a two- 

 headed rib ; but the other characters are more like those of Halteria, 

 which the author regarded as a near ally of the Crocodilia and 

 Chelouia, and as wrongly united with the Lacertilia. 



4. " On an Ornithosaurian from the Purbeck Limestone of Lang- 

 ton, near Swanage (Doratorhynchus validus)." By Prof. H. G. Seeley, 

 F.L.S., F.G.S. 



The author obtained these specimens (a lower jaw and a vertebra) 

 in 1868, and described them in the " Index to the Secondary Eep- 

 tilia, etc. in the Woodwardian Museum," in 1869, as Pterodactylus 

 macrurus. He now believed that the Ornithosaurian vertebrae from 

 the Cambridge Greensand, which have been regarded as caudal, are 

 really cervical, and therefore that the analogy on which this vertebra 

 was determined to be caudal cannot be sustained ; he proposed to 

 adopt for his species Prof. Owen's specific name validus, given in 

 1870 to a phalange of the wing finger from the same deposit. The 

 vertebra is 5 inches long, relatively less expanded at the ends 

 than similar vertebrae from the Cambridge Greensand, has strong 

 zygapoph}'sial processes, and a minute pneumatic foramen. 



The lower jaw, as preserved, is 12^ inches long. The symphysis 

 extends for 5 inches, and is about ^ of an inch deep, and divided 

 into two parts by a deep median groove. The teeth extended for 

 8 inches along the jaw, and about 7 or 8 occurred in the space of an 

 inch. They were directed outward in front, and became vertical 

 behind. Where the rami are fractured behind, they measure 2£ 

 inches from side to side. 



OBITTJAUY. 



SIR WILLIAM EDMOND LOGAN. 



LL.D., F.E.S., F.G S., V.P. Nat. Hist. Soc. Montreal. 



Yet another leading man has passed away — one whose name has 

 become familiar to geologists during fifty years of the most vigorous 

 growth of our science, and one whose labours and researches have 

 contributed in no small degree towards that development and progress 

 of ideas by which geology at the present day is characterized. 



