32 BULLETIN 161, UNITED STATES NATIONAL MUSEUM 



MASSILINA INAEQUALIS Cushman 



Plate 8, Figubes 6, 7 



Massilina inaequalis Cushman, Proc. U. S. Nat. Mus., vol. 59, p. 72, pi. 17, 

 figs. 12, 13, 1921 ; U. S. Nat. Mus. Bull. 104, pt. 6, p. 38, pi. 7, figs. 6 a-c, 1929. 



Test longer than broad, compressed, periphery squarely truncate; 

 chambers elongate, of uniform width, quadrangular in transverse 

 section ; sutures distinct, very slightly depressed ; wall smooth except 

 for numerous fine, linear depressions breaking up the evenness of 

 the surface ; aperture rounded, with a slight lip and a definite linear 

 tooth which is slightly bifid at the tip. Length, 1.3 mm. ; breadth, 

 0.6 mm. ; thickness, 0.18 mm. 



This species was originally described from the north coast of 

 Jamaica at Montego Bay, where it was fairly common. It has not 

 been recorded elsewhere, but very typical specimens occur in our 

 material from Vavau Anchorage, Tonga Islands, which seem to be 

 absolutely identical with the Jamaican specimens. 



MASSILINA AUSTRALIS, new species 



Plate 8, Figures 2 a, b 



Test very much compressed, the earliest chambers quinqueloculine, 

 later ones becoming planispiral, with slightly more than two cham- 

 bers making up a coil, periphery subacute; chambers distinct, very 

 slightly inflated; sutures fairly distinct, very slightly depressed be- 

 tween the last-formed chambers, but those of the earlier portion 

 obscured; wall fairly thin, usually translucent, finely pitted; aperture 

 elongate, narrow, with a slight lip, but no apertural tooth. Diameter, 

 0.8-1 mm. ; thickness, 0.1 mm. 



Holotype.—U.S.TSM. No. 14625, from Rotonga (=? Rarotonga, 

 Cook Islands), 7 fathoms. 



This species is very common at the type locality. It is probably 

 the same as that assigned by some authors to Massilina secans of 

 d'Orbigny. That species, however, in its typical development has a 

 very prominent quinqueloculine stage, and the later chambers have 

 a definite elongate tooth in the aperture. Our series of specimens 

 from the type locality shows that some of the last-formed chambers 

 have a wrinkled appearance as if due to stages of growth of the 

 chamber. The surface is dull and seems to be slightly pitted all 

 over. 



