201 



Hal. — Off Cape Jaffa, in 300 fathoms, 3 aiive and 12 

 valves; in 130 fathoms, 1 alive and 11 valves. 



Diagnosis. — It is very closely allied to the Cuspidaria 

 perrostrata, Dall, Bull. Mus. Comp. Zool., Harvard Coll., Cam- 

 bridge, xii., 1885-1886, p. 296, pi. ii., figs. 3a, 36, obtained in 

 339 fathoms, off Tortugas, and in 416 fathoms, gray ooze, 

 near Grenada. Also in Bull., 37, United States National 

 Mus., 1889, p. 66, pi. ii., figs. 3a, 36. My species has a shorter 

 rostrum, and the three bold ribs give it a distinct aspect. 

 Dall says there is a good deal of variation in this group, and 

 though my specimens vary scarcely at all, they may prove 

 to be a variety of Dall's species. This shell contributes ano- 

 ther new subgenus to the South Australian record, viz., Car- 

 diomya. 



Cuspidaria (lialonympha) ros, n. sp. PI. xiii., figs. 1 to 4. 



Shell small, inflated, pyriformly orbicular, very thin, 

 diaphanous. Umbos visible, tumid directed somewhat back- 

 wards. Post-dorsal border a gentle incurved slope ; anterior 

 nearly continuous with the posterior for about two millimetres, 

 then sweeping with an almost circular curve round the whole 

 front and ventral border, to merge into the obliquely upward 

 slope of the lower border of the rostrum, which is short, 

 rather tapering, and round-ended. 



Immediately beneath the minute approximate apex of 

 each umbo is a projection carrying a tiny elongate cartilage 

 pit. Some little distance behind this a wide-curved hollowed 

 lamina, like half the bowl of a spoon, stands out in each valve. 



There is a small elongate laminar cardinal tooth in front 

 of the fossette of the right valve ; none in the left. 



The surface is smooth, but for microscopic concentric 

 striae, chiefly near the ventral margin. 



Dim. — Antero-posterior diameter, 6 mm.; umbo-ventral, 

 4 ; sectional of closed valves, 2*5 mm. 



Locality. — 300 fathoms, off Cape Jaffa, 2 alive and 3 

 vah'cs: 130 fathoms, 3 alive and 14 valves. 



This new species introduces, for South Australia, a new 

 subgenus, Kalonympha, created by Dall and Smith, with 

 Nectra claviculata, Dall, as the type (Bull, of Mus. of Comp. 

 Zool., Harvard Coll., Cambridge, vol. xii., 1885-1886, p. 301). 

 It is characterized by an acute cardinal tooth in the right 

 valve, none in the left; a small central fossette, and by a 

 clavicular rib or myophore in the posterior part of each valve. 



Our shell is very closely allied to Necera claviculata, Dall, 

 Bull. Mus. Comp. Zool., 1881, vol. ix., p. 112, and Halo- 

 nympha claviculata, Dall, Bull. Mus. Comp. Zool., Harvard 



