60 P roceedings of the Royal Society of Victoria. 



In Olenoides, Meek, taking the type species, O. iypicalis, 

 Walcott,* I fail to trace any resemblance to our fossils, for, 

 although the glabella is square-oblong, with parallel straight 

 sides, the furrows on the glabella are well-marked ; there are no 

 circumscribed lobes ; the eye-lobes are very long, approaching 

 those of Olenetlus, whilst the fixed cheeks and facial sutures are 

 quite unlike those of Dinesus. On the other hand, the pygidium 

 in Olenoides is provided with spines along the margin. When, 

 however, we examine O. quadriceps^ Hall and Whitfield, sp., the 

 form indicated by Mr. Walcott in his letters to me, the resem- 

 blance is very much stronger. There is the same almost quadrate, 

 or square-oblong glabella, straight parallel sides, small eye-lobes, 

 but with faint grooves on the glabella, and no circumscribed 

 lobes. Whilst admitting a resemblance, it does not seem to me 

 to be of that intimate character necessary for the incorporation 

 of our specimens in the same genus with O. quadriceps. At the 

 same time the latter does not strike me as possessing much in 

 common with Olenoides., as typified by O. typicalis, Walcott. 



Dames refers O. quadriceps to his genus Dorypyge ;\ but 

 Walcott| thinks that the latter may be only synonymous with 

 Olenoides. As defined by its author, Dorypyge possesses three 

 pairs of glabella furrows, and a facial suture not unlike that of 

 my proposed new genus, but without any trace of circumscribed 

 lobes. On the other hand the margin of the pygidium, ,as in 

 Dinesus, is spined, and closely allied to that of the latter. As 

 regards Dorypyge generally, Mr. Wal<"ott makes the following 

 remarks :i< " I have placed the two species|| under the genus 

 Olenoides while waiting for proof of the character of the border 

 of the pygidium of the genus. I have very little doubt of its 

 being spinous, and if it is so, the species described by Dr. Dames 

 will probably fall within its limits, and the genus Dorypyge be 

 placed as a synonym of Olenoides. In the event of Olenoides 

 nevadensis being generically distinct from Dorypyge Kichthofeni, 



» Bull. U.S. Geol. Survey, 1886, Xo. 30, p. 183, t. 2,';, f. 2. The actual type of the genus Is 

 O. iievadens-is. Meek, but of this the cephalic-shield is unknown. 



t Kichthofen's China, 1883, iv., p. 23. 



t Bull. U.S. Geol. Survey, 1886, No. 30, p. 222. 



§ Bull. U.S. Geol. Survey, 188G, No. 30, p. 222. 



II Olenoides quadricep!t, H. and W., and 0. wahsatchenxi.^i (=Dikeloc<>phalasr //othicus, 

 11. and W.) 



