76 REC0BD8 OF THE AUSTKALIAN MUSEUM. 



Each thread-like lyrula of the sculpture is separated from its 

 neighbour by several times its own thickness, the obliquity of the 

 lyrulpe on the upper part of each whorl being changed on the 

 straight-walled portion to a perfectly vertical direction. The 

 upper part of the inner lip, although not forming a callosity, is 

 revolute, slightly projecting over the umbilicus. The aperture 

 was long oval, angled on the outer lip by the principal keel of the 

 body whorl. 



Log. and Horizuji.—Grordon. River, West Tasmania. Gordon 

 River Limestone, Lower Silurian. 



Trochonema? nodosa, sp. nov. 



PL XV., Figs. 9, 10. 



Worthenia, sp. nov., Ratte, Proc. Linn. Soc. N.S. Wales, x., 1885, 

 pt. 1, p. 80, t. 9, f. 1 and 2. 



Sp. char. — Shell turbinate, but not depressed ; whorls more 

 than four (four in part only preserved), the body whorl apparently 

 not free, each whorl horizontal or nearly so on its upper portion 

 around the suture, vertical or straight-walled in the lower ; all, 

 except the body whorl, bear two keels, the latter three, the upper- 

 most keel in each case demarcating the two portions of the whorls, 

 and earring a number of blunt nodes, or tubercles, which on the 

 body whorl become of a variciform nature, and more pronounced 

 with the growth of the whorl ; the second keel is midway between 

 that just mentioned and the suture, and with the third on the 

 body whorl is nodose also. Mouth generally oval, vertically elon- 

 gated ; outer lip quadrangular ; inner lip and minute sculpture 

 not preserved ; umbilicus deep and apparently open. 



Obs. — Had not Mr. Ratte figured this shell, and referred it to 

 Worthenia (with which it has no connection), without a specific 

 name, I should not have noticed it in consequence of its poor state 

 of preservation. I am even doubtful of its proper generic resting- 

 place from the same cause, but Trochonema, so far as I can judge, 

 seems to be the most appropriate genus. At the same time it departs 

 from the majority of species referred to the latter by the nodose 

 nature of the encircling keels. There is one species of this genus, 

 however, similarly ornamented — T. yandellana, Hall it Whitfield,* 

 from the North American Corniferous Limestone, but otherwise 

 distinct from T. ? nodosa. It may even be related to our old 

 friend Buccinum breve, Sby., of the British Devonian rocks, and 

 which Whidborne has of late referred! to the recent genus Liotia, 

 Gray, without, however, in my opinion, sufficient reason. 



* 24th Ann. Rep. N. York State Cab., 1872, p. 194 ; 27th ibid., 1875, t. 

 13, f. 3 ; Nettelroth, Kentucky Fossil Shells, 1889, t. 20, f . 3. 

 t Men. Dev. Fauna S. England, 1892, pt. 4, p. 271. 



