30 AUSTRALASIAN ANTARCTIC EXPEDITION. 
CyAMIUM ROTUNDATUM Thiele. 
Cyamium rotundatum Thiele, Deutsch. Siidpol. Exped., xiii., 1912, p. 231, pl. xvi, 
fig. 20. 
One specimen dredged, December 14th, 1913, in 45-50 fathoms, Commonwealth 
Bay; two, December 28th, 1913, in 288 fathoms, ooze, off the Eastern Barrier of 
Adelie Land, in South Lat. 66° 55’ and East Long. 145° 21’; and one, January 28th, 
1914, in 240 fathoms, ooze, off the Shackleton Ice-shelf, in South Lat. 65° 20’ and 
Hast Long. 95° 27’. 
Touching Cyamium, it may be noted that Thiele (op. cit., p. 270) has transferred 
Diplodonta incerta Smith to Cyamium rather than to Cyaniomactra. Judging from 
nomenclature there is an insistent demand for the latter genus because, subsequent 
to its introduction by Bernard in 1897, it has been independently recognised as 
Heteromactra by Lamy in 1906, as Acolus by Jukes Brown in 1913, and as Jukesena 
by Iredale in 1915. , 
VENERICARDIA ASTARTOIDES von Martens. 
(Plate IIL., figs. 33, 34.) 
Cardita astartoides von Martens, Sitz. Gesell. Nat. Fr. Berlin, 1878, p. 25; Jd., Smith, 
Chall. Rep. Zool., xiii., 1885, p. 212, pl. xv., fig. 2; and Jd., Coll., “Southern 
Cross,” 1902, p. 211; Id., Nat. Antarct. Exped., ii., 1907, Lamell., p. 2; and Jd., 
“ Terra Nova” Exped., ii., 1915, Moll., p. 77; Id., Lamy, 1st Expéd. Antarct. 
Franc., Moll., 1906, p. 14; and 2nd Expéd. Antarct. Frang., Moll., 1911., p. 
21; and Bull. Mus. Hist. Nat., xxi., 1915, p. 74; Id., Hedley, Brit. Antarct. 
Exped., ii., 1911., Moll., p.3; Jd., Thiele, Deutsch. Siidpol. Exped., xii, 1912, 
p. 230, pl. xvii, fig. 10. 
The series gathered by this Expedition range from 6 to 29mm. in length. It shows 
that as the species increases in size the radial sculpture becomes fainter and, as Mr. 
Smith has already observed, the height increases in proportion to the length. Without 
the aid of a connecting series the younger individuals would scarcely be recognised 
to be the same species as the adult. An illustration of a half-grown example, 17mm. 
long and 13mm. high, is, therefore, here provided to assist identification. 
One living shell was dredged, January 27th, 1914, from 120 fathoms, hard ground, 
in the Davis Sea, in South Lat. 66° 8’ and East Long. 94° 17’. Another and some odd 
valves, January 31st, 1914, from 110 fathoms, off the Shackleton Ice-shelf, in South 
Lat. 64° 32’ and Hast Long. 97° 20’. 
PryCHOCARDIA VANHOFFENI Thiele. 
Ptychocardia vanhoffeni Thiele, Deutsch. Siidpol. Exped., xiii., 1912, p. 232, pl. xvii., 
fig. 24. 
“One right valve, 10mm. high, dredged, December 2Ist, 1913, in 55-60 fathoms, 
Commonwealth Bay. 
