Mr Etlieridge on Fossils from Bowen River Coalfield. 295 



valve covered by a series of short, blunt, somewhat projecting 

 tubercles ; surface of the dorsal valve similarly ornamented, 

 but the concentric lamina3 appear to be closer, the spines 

 more numerous, closer toQ-ether, and longer than on the ven- 

 tral valve ; near the front edge of the valve the lamellae 

 become very close and numerous, and assume a strongly 

 imbricated appearance. The greatest concavity of the dorsal 

 valve is just below or in front of the hinge line, where it 

 appears to become much pressed in. The shell at times 

 assumes a slightly irregular aspect, with an inclination or 

 oblique tendency towards one side or the other; the front 

 margin is rounded and continuous, and shows no indication 

 of an indentation or sinuosity. 



Ohs. — After much consideration of the subject in all its 

 bearings, and a long correspondence with my friend Mr 

 Davidson, I have provisionally kept apart from the previous 

 S. Clarhei certain Queensland Strophalosice with very concave 

 dorsal valves, and have referred them to Professor King's >S'. 

 Gerardi. On tliis subject Mr Davidson wrote me as follows : 

 " The dorsal valves are so very concave that I should hardly 

 like to consider S. Clarhei and S. Gerardi as one, and to place 

 your father's species as a synonym of S. Gerardi. We have 

 not as yet, so far as I can see, any reliable interiors of the 

 ventral valve of S. Gerardi, and I think it would be safer to 

 keep it and >S'. Clarhei separate, unless you have some speci- 

 mens to lead you to positively combine the two in one." 



To the courtesy of Professor W. King of Galway I am in- 

 debted for the loan of the type of his S. Gerardi, which has 

 enabled me to make the closest of comparisons with the 

 Queensland shells I have here provisionally placed under 

 that species, and the only essential difference that I can point 

 out is, that in the type of S. Gerardi, the form of the shell is 

 much more transverse than in the Queensland examples now 

 under notice, the general form of the latter being decidedly 

 inclined to the deltoid. I, however, presume that in such a 

 variable genus as Stro2olialosia this would, in the absence of 

 other characters, count for very little. 



Notwithstanding the flat valve of typical specimens of S. 

 Clarhei, it is just possible that it and the shells now referred 



