LOWER CRETACEOUS FOSSILS — ETHERIDGE. 161 



In the specimens figured in the " Transactions of the Royal 

 Society of New South Wales," and again refigured in the "Geology 

 and Palaeontology of Queensland," there is an indication of an oval 

 margin or lip, in that the terminal costa? are much more prominent, 

 and on the centre of the venter are backwardly curved, forming 

 a kind of shallow "hyponomic" sinus. 



The tuberculation of this form is very marked. There is a line 

 of prominent, almost spine-like tubercles, supra-dorsal in position, 

 which unite the costa?, or most of them, into bundles of two or 

 three, but instead of then passing over the dorsum as single ribs, 

 as is usually the case, the costa? again split up into a like number 

 as before. Along each side the median line of the venter there 

 is a further row of small pimple-like nodes, one to each costa. 



There is another specimen that may be only a variety of C. 

 laqueus (or possibly a distinct species) in which the venter is 

 much broader, the costa? far more numerous and finer, but with 

 the same marked supra-dorsal tubercles as in C. laqueus proper, 

 although the rows of pimple-like nodes along the abdominal angles 

 are absent. Again, at one end of the specimen there certainly 

 seems to be a definite margin representing the lip of the living 

 chamber with a shallow sinus, but in this instance the marginal 

 costa? are not elevated above the others. 



This form is represented in the Point Charles beds of the 

 Northern Territory of South Australia by two indifferently pre- 

 served specimens. For the present I regard these fossils merely 

 as a variety of C. laqueus. 



In the "Geology and Palaeontology of Queensland," etc., 

 another specimen was figured, 1 ' 1 apparently a portion of a shaft, 

 and evident]}' related to C. laque.us in that some of the costa? are 

 gathered in fasciculi by tubercles more nearly lateral than supra- 

 dorsal, but as in the above species again dividing to pass over the 

 dorsum. The identity of this specimen must for the present 

 remain in doubt. 



Loc. — Aiamac Well (at 184ft.), Aramac, Thomson River, 

 Central Queensland [G.S.Q.]. Fifteen miles south-west of Hugh- 

 enden, North-Central Queensland [G.S.Q.]. Tower Hill, Lands- 

 borough Creek, a head tributary of the Thomson River, North 

 Queensland [Q.M.]. Barcoo, Ward and Nive Rivers District, 

 South Queensland [A.M. (H. W. Bl omfield)\ Dalhousie Springs, 

 north of Oodnadatta, Central Australia [G.S.S.A. and A.M.]. 

 (?)Point Charles Lighthouse, Port Darwin [A.M. (Messrs. Christy 

 and Godfrey)]. 



•^'Etherklge— Geol. Pal. Q'land., &c, 1892, PL xxxiii., figs. 5, G. 



