■296 



THETIS SCIENTIFIC RESULTS. 



The "Thetis" took this off Port Kembla in 63-75 fathoms, and 

 •oft Cape Three Points in 41-50 fathoms. 



CYRILLA, A. Admns. 



CYRILLA DALLI, sp. no v. 



(Fig. 44.) 



Stations 13, 49. 



Shell minute, inflated, oblique, produced on the posterior ven- 

 tral side, glossy, slightly concentrically striated. Colour white, 



under a thick, horny, brittle, brown 

 epidermis, substance slightly nacreous. 

 Umbones obtuse, rather distant 

 Chondrophore a deep triangular pit 

 under the umbo, posterior to which is a 

 long, narrow groove, apparentl}' for the 

 reception of the ligament. Hinge plate 

 broad and short, projecting below, bear- 

 ing three long, narrow, outstanding 

 cardinals, and on either side of these a 

 rudimentary tooth. Left valve with a 

 long, strong posterior lateral tooth, 

 recei\ed into a deep socket in the right. 

 The pallial line is slightly sinuate on 

 approaching the posterior adductor scar, 

 which is low down and well developed. 

 Margin of vah e smooth and bevel-edged. 

 Length, 1 -2 ; height, 1 05 ; depth of 

 single valve, '35 mm. 



CiRILLA DALLI. 



Fig. 44. This species, the third and smallest 



CyriUa, adds a genus to the Australian 

 fauna. It is named for Dr. W. H. Dall, as a slight but grateful 

 acknowledgment of the help which his " Tertiary Fauna of 

 Florida " has been to me in studying this and other forms. My 

 illustration shows the left valve from above and from within. 



Many separate valves, and a few coloured and in contact, were 

 taken off Port Kembla in 63-75 fathoms, and off Cape Three 

 Points in 41-50 fathoms. 



