568 MESSES. E. HEEON-ALLEN AA"D A. EAELAND ON THE 



set somewhat obliquely, so that the general arrangement is on the same plan as in 

 31. hosciana. In young specimens the chambers are often divided from each other 

 at the oral and aboral extremities by an open space between them, which perforates 

 the entire test as shown in Brady's figures of Spiroloculina acutimargo Brady and 

 S. grata Terquem. 



The appearance of this little shell is strikingly constant and characteristic, the 

 sutures, which in most miliolids are marked by slight depressions or by flush or even 

 limbate sutural lines, being entirely absent. The whole shell suggests a simple tube of 

 crescentiform section, invariably narrowing towards the apertural end of each chamber, 

 and coiled on itself in milioline fashion. It is this narrowing which gives the 

 transverse arrangement of the early chambers as compared with the final pair. Our 

 species is to some extent isomorphous with SpirolocuUna acutimargo Brady, but diff'ers 

 from that form in the rounded and embracing character of its chambers, the eiitire 

 absence of any keel, and the milioline plan of growth. Its affinities in the milioline 

 group are with M. gracilis (d'Orb.). 



The species is fairly generally distributed, but never very abundant, the best and 

 most numerous examples being found at Stn. 5. It also occurs at Vavau, Friendly Is., 

 Pacific, 16 fms. 



Length averages "o-'Sf) mm., breadth •18--24 mm. 



52. Miliolina rotunda (d'Orbigny). (PL XLII. figs. 27-30.) 



Triloculina rotunda d'Orbigny, 1826, TMC. p. 299. no. 4. 



„ Schlumberger, 1893, MGM. p. 64, pi. i. figs. 48-50; text-figs. 11, 12. 

 Miliolina rotunda Millett, ]898, etc., FM. 1898, p. 267, pi. v. figs. 15, 16. 

 „ „ Sidebottom, 1904, etc., RFC. 1904, p. 8. 



Heron-Allen & Earland, 1913, CI. p. 25. 

 „ „ Wiesner, 1912, AM. p. 225. 



11 Stations. 



Not very common except at Stns. 3, 12, and ?X, where the specimens were large, 

 typical, and very abundant. At Stns. 1 and 11 a smaller type occurs similar to 

 Millett's Malay figures, and, like those, very variable, both biloculine and tri- 

 loculine specimens (but chiefly the former) occurring. This small and variable 

 type differs considerably from the large d'Orbignyan type in its shell-texture. The 

 large type has a smooth, thick, and highly polished surface ; while the shell in 

 the small type is thin, irregular in surface, or marked with lines of growth, and 

 often matt or even sclerotic. 



53. Miliolina anconensis (Schultze). 



Miliola anconensis Schultze, 1854, OP. p. 58, pi. ii. figs. 12, 13. 

 10 Stcciions. 



This rather well-marked type, with its triloculine test and large gaping mouth. 



