444 Dr. F. Huene — Saurlschia and Ornithischia. 



Fig. 



3. Marssonopora dispersa (Hagenow). A piece of a zoarium showing bilateral 



branching and consisting of two normal zooecia and the caudal ends of 

 five others, three of which bear small avicularia. The lower normal 

 zooecium (of which the capitular end only is shown) bears an ovicell. 

 X about 43 diameters. British Museum specimen No. D. 11498. 

 Senonian, zone of Belemnitella mucronata. Eiigen I., Gennan Baltic. 



4. Dacryopora gutta, "n.sp. A piece of zoarium showing bilateral branching 



and consisting of two zooecia, encrusting a piece of shell of Inoceramus 

 lamarckii, Parkinson. The caudal portion of one zooecium traverses 

 a ridge in the shell and consequently appears wavy, x about 33 

 diameters. British Museum specimen D. 27955. Senonian, top of zone 

 of Micraster cortestudinarium or base of zone of M. coranguinuvi, 

 Chatham, Kent. W. Gamble Coll. 



5. Dacryopora gutta, n.sp. A single zooecium from the type-specimen 



X about 37 diameters. British Museum specimen D. 27982. Senonian, 

 zone of Micraster cortestudinarium. Pit west of large pit on Offham 

 Hill, Lewes, Sussex. C. T. Gaster Coll. 



III. — Satteischia and Oenithischia. 

 By Dr. F. HUENE. 

 FN 1888 the late Professor H. G. Seelev pointed out for the first 

 L time (Eep. Brit. Assoc. Adv. Sci., IS'SS, pp. 698-9) that Owens' 

 order * Dinosauria ' should be divided into two great natural groups, 

 especially on account of their pelvis. He called them SaUrischia 

 (= ' Theropoda ' + 'Sauropoda') and Ornitliischia (= ' Orthopoda'). 

 He maintained his classification until liis death in 1909, but nobody 

 followed him. Only in 1907 did the present writer accept this 

 classification and gave new evidences for it, but still was of opinion 

 that these two groups only were ramifications of one natui'al unity, 

 the ' Dinosauria '. But now, for several years, the writer has come 

 to the conclusion that the ' Dinosauria ' are not of monophyletic 

 origin, but have developed from different points, and should therefore 

 be considered as two distinct natural orders. Superficial similarities 

 have been valued too higlily, such as general form and size of the body, 

 bipedal locomotion in two large groups, certain similarities in the 

 formation of the foot, the femur, the humerus, and the shoulder- 

 girdle. 



The most striking difference between the Saurischia and the 

 Ornithischia is in the pelvis, as is now generally well known. Even 

 in their oldest known representatives there is no convergence at all 

 in this respect. In the Ornithischia tlie facial part of the skull is 

 prolonged and without prseorbital openings, except in the most 

 primitive forms with a very small fenesti'a ; the dentition is multiplied 

 and specialized ; the extremities of the jaws are toothless (except in 

 the ^xumirve SypsilophodoTi,'), and in the lower jaw (in one group also in 

 the upper jaw) anew symphysial bone has been formed; the praemaxilla 

 is of enormous size, its posterior extreraitv being intercalated 

 between maxilla and nasal, and even reaching the lacrymal or 

 the adlacrymal ; the internal bony nasal openings are of enormous 

 size, and the formation of the rest of the palate is characteristic; 

 the processus coronoideus in the lower jaw is high, the quadrate is 

 free ; and the supraorbital forms part of the roof of the skull (as 



