Chapman. — On some Foraminifera and Ostracoda. 85 



Bradv regards this species as essentially of deep-water 

 habitat, and it is consequently not surprising to find it but 

 rarely in the sounding oft Great Barrier Island. One of the 

 specimens was accidentally broken, and showed the test to be 

 very thin, and formed of almost uniform sand-grains very 

 neath' cemented, and having a smooth surface both on the 

 interior and exterior. In our specimen the chambers increase 

 very rapidly in size with growth. 



H. globiyeriniformc has been recorded from the " Chal- 

 lenger " sta. 169, at 700 fathoms. 



Haplophragmium calcareum, Brady. 



Haplophragmium calcareum, Brady, 1884, Rep. Chall., vol. ix, 

 p. 302, pi. xxxiii, figs. 5-12. 



A typical specimen occurs in our series. It is almost 

 entirely a tropical species, an exception occurring, m the 

 " Challenger " records, off Sydney, 410 fathoms. 



Subfamilv Trochamminin^e. 



Genus Ammodiscus, Reuss. 



Ammodiscus tenuis, Brady. 



Ammodiscus tenuis, Brady, 1881, Quart. Journ. Micr. Sci., 

 vol. xxi, n.s., p. 51. Id., 1884, Bep. Chall., vol. ix, p. 332, 

 pi. xxxviii, figs. 4-6. 



The form distinguished as A. tenuis occurs with some 

 frequency in our sounding. It has been previously recorded,* 

 in company with A. incertiis, d'Orb., from a neighbouring 

 locality — station 169; and Dr. Brady, indeed, threw out the 

 suggestion that the form was perhaps only a local variety of 

 the better-known and ubiquitous species J., incertus. 



Dr. Rhumbler has also remarked about this species,! 

 " Die Scheibe ist diinner, die welcher sie vielleicht die mega- 

 lospharische Form darstellt." 



A general examination of our specimens showed the initial 

 portion of the coil in every case to commence with a more 

 or less swollen " protoconch " or (?) megalosphere. This is 

 subject to much variation in size, which at first seemed to 

 lend support to the idea that a microsphere might be present 

 in A. tenuis. To conclusively settle this doubtful point, how- 

 ever, it will necessitate the examination of a further series of 

 specimens. 



* Rep. Chall., Summary of Results, vol. i, 1895, p. 605. 

 f Archiv fiir Protistenkunde, vol. iii, 1903, p. 281. 



