72 RECORDS OF THE AUSTRALIAN MTTSETTM. 



of Mr. G. B. Pritchard, who has done much to advance our know- 

 ledge of Victorian Palaeontology. 



Log. and Horizon. — Cave Hill Quarries, Lilydale, Upper Yarra 

 District, Victoria. Lilydale Limestone, Upper Silurian ; pre- 

 sented by Messrs. J. Hinder and E. Smith. 



Genus Gyrodoma, gen. nov.* 

 Gyrodoma etheridgei, CresweU, sp. 

 PL xvi., Fig. 1. 



Eunema etheridgei, Creswell, Proc. R. Soc. Vict., 1893, v. (n.s,), 

 p. 42, t. 8, f. 2, (2 figs.). 

 Qhs. — Mr. Ores well's figure represents an imperfect shell, and 

 those now before me are also in the same condition, but suflicient 

 characters are deducable to show that it is not referable to 

 Eunema, which is an imperforate genus, with angular whorls. 

 In G. etheridgei, on the other hand the whorls are boldly rounded, 

 certainly seven in number and possibly more ; in PL xvi.. Fig. 1 

 seven are visible, whilst Creswell assumed five to be the number. 

 In the latter's left hand figure, as above quoted, there seems to 

 me to be an umbilicus, although no mention is made of this in the 

 description. In PL xvi., Fig. 1, a distinct and rather flat or 

 depressed band is visible, bounded by two lyrte that are certainly 

 more prominent than the remainder encircling the whorls. Mr. 

 Oreswell's figures both distinctly portray two bands side by side, 

 but the example now figured has but one. If a double band does 

 exist on some specimens, it indicates a departure towards the 

 Cretaceous genus Disopeta, Gardner. The whorls decrease in size 

 rapidly, the inner lip is almost straight, and with the anterior 

 termination of the outer lip describes nearly a right angle. 



The presence of the regular spiral lyme distinguishes the proposed 

 new genus from the allied Goniostropha, CEhlert, Cnlocaulus, 

 Qiihlert, Hormotoma, Salter, Caliendrum, Brown, Cerithioides, 

 Ilaugliton, Stegocn'lia, Donald, Hypergonia, Donald, and Glypho- 

 deta, Donald, aided in some instances by the rounded whorls of 

 Gyrodoma, and the position of the band. The nonderolement of 

 the whorls distinguishes the latter from Loxoplocus, Fischer, and 

 the absence of all tuberculation from Murchiso7iia, the genus 

 proper in its restricted sense. If an umbilicus exists it cannot be 

 a Pithodea, De Kon. I therefore conclude it is a new section of 

 Murchisonia and call it Gyrodoma. 



hoc. and Horizon. — Cave Hill Quarries, Lilydale, Upper Yarra 

 District, Victoria. Lilydale Limestone, Upper Silurian ; pre- 

 sented by Mr. J. Hinder. 



* Gyro, to turn round, and domus, a house. 



