282 Proceedings of the Royal Physical Society. 



ing (No. 83) ; Parrot Creek, four and a quarter miles up (No. 

 148) ; both in Marine Series. 

 Collector. — E. L. Jack, Esq. 



Genus Orthotetes — Fischer. 



Orthotetes erenistria, var. senilis — Phillips. — PL VIIL, 

 figs. 12-15. 



Spirifcr senilis, Pliill., Geol. Yorksh., 1836, ii., p. 216, t. 9, f. 5. 

 Btrcptorliynchus erenistria, var. senilis, Davidson, Mon. Brit. Carb. Brach., 



t. 27, f. 2-2«, 3-3a, and 4. 

 Leptcena senilis, M'Coy, Brit. Pal. Foss., 1853, fas. 3, p. 45a. 



Ohs. — There can be no mistaking this semi-conical, irregular, 

 and gnarled-looking variety of the widely spread Orthotetes 

 erenistria. The ordinary form of the species has been before 

 recorded from Australian Carboniferous rocks,* but, so far as I 

 am aware, the variety senilis has not previously been met with. 



The Queensland specimens have, in common with British 

 examples, the semi-conic ventral valve, with step-like inter- 

 ruptions, " produced by two or three very large and irregular 

 concentric undulations," the elevated but not incurved beak, 

 and the wide area with its convex deltidium. Similarly, the 

 dorsal valve exhibits the straight hinge line, evenly convex 

 surface, and much less marked undulations. The striation of 

 the valves likewise appears to be identical, and there are also 

 the same concentric laminations of the area and deltidium as 

 seen in some British examples. In these shells from Queens- 

 land the sheUy matter is decidedly and distinctly punctate, 

 and when the surface is at all worn the punctee are every- 

 where visible, and more especially on the area. I believe the 

 punctate structure of the shell in Orthotetes (= Streptorhyn- 

 ehiis) has not been generally recognised, for in the generic 

 descriptions of it given by all the best authors, the shell is 

 said to be impunctate. However, that most accurate observer, 

 Professor W. King, has not omitted to notice this peculiarity 

 in a Permian species of the genus, 0. pelargonatus (Schlo- 

 theim).-f- On mentioning the existence of these perforations 

 in the Australian shells to Mr Davidson, he informed me 



* De Koninck : "Foss. Pal. Nonv-Galles du Sud.," 1877, pt. 3, p. 213. 

 + Mon. Permian Foss. England, p. 109. 



