94 



Supplemental Notes on the Palliobranghs 

 OF THE Older Tertiary of Australia, and 

 A Description of a Ne^a^ Species of 

 Rhynchonella. 



By Professor Ealph Tate, F.G.S., F.L.S., &c. 



[Read October 6, 1885.] 



The following notes are addenda to my paper on "The 

 Palliobraucbs of the Older Tertiary of Australia," published iu 

 these transactions for the year 1880 : — 



I. New Species. 

 Rhynchonella Baileyana, Tate. Plate vi., figs. 3a— 3c. 



Hef. — Southern Science Eecord, January, 1885, p. 1. 



Shell transversely ovate-trigonal, sub-depressed ; dorsal 

 valve regularly convex from the umbo to the middle, thence 

 flattish to the front of the mesial fold, which is broad and not 

 very prominent ; the ventral valve is less convex, with a broad 

 sinus of moderate depth commencing at half the distance from 

 the beak and extending to the front. The anterior-fourth of 

 each valve is plaited and circumscribed by a conspicuous fold 

 of growth ; there are seven plaits on the mesial fold and 

 about four on each lateral area. The mesial fold occupies 

 about one-third of the front of the shell, rising abruptly from 

 the lateral areas. The beak is very small, moderately pro- 

 duced, with a minute circular foramen under its angular and 

 slightly-incurved extremity which is surrounded and separated 

 from the hinge line by a deltidium of two pieces. 



Length, 25 ; breadth, 18 ; thickness, 12 millimetres. 



The species is dedicated to the memory of Mr. John P. 

 Bailey, late of Melbourne, to whose enthusiasm for science he 

 recently fell a martyr, by whom it was collected at Jemmy's 

 Point, at the entrance to the Gippsland Lakes. 



TilujnclioneUa 'Baileyana is an interesting addition to the 

 palliobranch fauna of the Australian Tertiary period, inasmuch 

 as it differs so widely from living and Tertiar}^ species, and re- 

 calls some Mesozoic ones. I do not know of any other fossil 

 which has so depressed and broadly oval form conjoined with 

 marginal plications and a small sub-erect beak as it jDOssesses 



II. Species still Liti>'^g. 



Rhynchonella squamosa, Hutton. 



This species in a living state was taken off south of Iver- 



guelen Island during the Challenger expedition, and has been 



redeseribed by Mr. Davidson in Brachiopoda of the Challenger 



Exped., t. 4, f. 14, p. 59 (1880), as R. nigricans, var. pixydata. 



