1872.] ETHrEEIDGE — QUEEirSLAND FOSSILS. 345 



Ammonites Sutheexandi, Ether. PI. XXI. fig. 4. 



Shell discoidal; whorls three or four, with flattened sides, and 

 six or seven transverse wavy furrows on the outer whorl ; these are 

 slightly inflected forwards on the sides of the shell, and pass over 

 the back at right angles to the keel ; back sharply convex ; the 

 surface of the shell appears to have been marked by, or ornamented 

 with, fine lines or striae apparently arranged at a different angle from 

 the sulci or furrows. 



Umbilicus small, well exposed, its walls rounded ; aperture oval, 

 elongated, or acutely ovate. 



Obs. A very small portion only of the shell remains upon the side 

 of the outer whorl, between the last two sulci, and shows faintly the 

 fine undulating lines. The sutures are so indistinctly marked that 

 I cannot refer them to any known species. 



A. Sutherlandi has affinity with A. cassida, Raspail, from the 

 Neocomian (Lycee, p. 115, no. 2 ; Ann. des Sc. d'Observation, t. iii. 

 pi. 11. f. 3); but the sulci or furrows are fewer and wider, and 

 the umbilicus smaller. None of the group Ligati, in the fine 

 Indian collection named and described by Ferd. Stoliczka (Mem. 

 Geol. Surv. of India) affords any clue to the form from Queensland, 

 although some twenty- eight Indian species belong to this group. 

 The smallness of the umbilical cavity and depth of the outer whorl re- 

 move this form from any species with which we can ally or compare it. 



I name this species after one of the earnest explorers of Queens- 

 land. 



Ammonites Betjdanti, Brongn., var. Mitchelli, Ether. PI. XXIII. 



Shell discoidal, compressed, composed of four or five volutions or 

 whorls rapidly increasing ; sides nearly flat, ornamented with gently 

 elevated undulating or sigmoidal ribs or folds bending towards the 

 aperture, and about half an inch apart on the middle of the whorl. 

 These and the interspaces are occupied by delicately arranged equi- 

 distant parallel lines or costse, which pass over the back ; aperture oval, 

 back rounded and narrow, no keel ; inner whorls exposed ; walls of 

 umbilical cavity angular, flat-sided, or bevelled and smooth. 



Obs. This Ammonite, in its intermittent folds, involution of 

 whorls, and general habit much resembles A. Beudanti, D'Orb., from 

 the Gault of England and France, to which it is certainly closely 

 allied. 



Since writing the above I have seen Prof. M'Coy's description of 

 A. Flindersi. It agrees so closely with my own that I believe them 

 to be the same species. No figure accompanies M'Coy's description, 

 which is to be regretted. Should, however, our shell be the 

 A. Flindersi of M'Coy, the above name must be abandoned, unless 

 M'Coy's form is really the A. Beudanti, D'Orb. I name the varietal 

 form after J. L. Mitchell, Esq., whose early labours, researches, 

 and travels in Australia deserve the highest consideration. Figure 

 reduced 5. 



Log. Hughenden. Form. Lower Cretaceous. 

 VOL. XXVIII. — paet i. 2 b 



