38 



Brachiopoda. 



Genus Rhynchonella, Fischer. 



(Notice Foss. Gouv. Moscou, 1809, p. 35). 



Rhynchonella decimplicata, J. de C. Sby. 



Wiyndionclla decimplicata (J. de C. Sby.), Davidson, Mon. Brit. Sil. 

 Brachiopoda, 1869, III., Pt. 7, No. 3, p. 177, t. 23, f. 20-24. 



Bhynchonella decimplicata^ M'Coy, Prod. Pal. Vict., Dec. V., 1877, 



p. 26, t. 47, f. 3-6. 



Ohs. — A number of crushed examples of this species are 

 associated with the remains of Cromus 3Iurchisoni, but are 

 sufficiently well preserved to exhibit the distinctive features 

 of the species. JR. decimplicata has already been met with 

 in the Upper Silurian of Victoria by M'Coy, and although 

 figured by Mr. R. M. Johnston in his '' Geology of Tas- 

 mania," is not, I think, from Tasmanian rocks. 



Log. — Heazlewood, in a grey-blue schistoze rock. • 



Rhynchonella cuneata, Dalman. 



PL, Fig. 16. 



Bhynchonella cuneata (Dalman), Davidson, Mon. Brit. Sil. Brachio- 

 poda, 1867, Pt. 7, No. 2, p. 164, t. 21, f. 7-11. 



Tthjnchonella cuneata^ Johnston, Syst. T^cc. Geol. Tas., 1888, t. 7, f. 9. 



Ohs. — An impression of a single ventral valve possessing 

 the general cliaracters of this species tends to confirm Mr. 

 Johnston's recognition of it as a Tasmanian fossil, but the 

 number of costse seem to separate it as a variety. In R. 

 cuneata^ Dalm., the costae are from ten to fourteen, of 

 which four or five occur on the fold of the dorsal v^alve, 

 and three or four in the ?inus of the ventral. On the 

 impression from Zeehan there are ten costae, but only one 

 of these occurs in the sinus. The shell evidently possessed 

 the same cuneate form and elevated umbo. There is, 

 however, no trace on this cast of a punctate surface siuiilar 

 to that of the American shell. Prof. James Hall has 

 referred to this species, and erected it into a separate 

 genus under the name of Rhynchotreta ; ^ neither did Dr. 

 T. Davidson recognise this structure in European examples 

 of Ji. cuneata. 



Johnston's figure, from the shading, I take to be a dorsal 

 valve, with three costae on the fold. 



Loc' — Zeehan, in a blue-grey schistose rock. 



1 28th Ann. Report N. York State Cab. Nat. Hist., 1879, p. 1G6. 



