MILIOLIDAE 47 



8. Pyrgo patagonica (d'Orbigny) (F 7) (SG 7). 

 Five stations: 181, 182, 366, 385; WS 482. 



Frequent at St. WS 482 at a depth of 100 m., rare or very rare elsewhere. All the 

 stations are in shallow water except St. 385 which is in the Drake Strait, depth 3638 m. 

 Here two very pauperate specimens, doubtfully referable to the species, were found. 



9. Pyrgo peruviana (d'Orbigny) (F 8). 

 Five stations: 167, 175, 181, 182, 196. 



Large specimens are frequent at Sts. 175 and 182; less common and smaller at the 

 other stations. 



10. Pyrgo globulus (Bornemann) (F 11) (SG 10). 

 Three stations: 170, 181, 182. 



Common and attaining a large size at all of these stations, the depth ranging between 

 641 and 710 m. 



Genus Spiroloculina, d'Orbigny, 1826 



11. Spiroloculina pusilla, sp.n. (Plate I, figs. 3, 4). 



SpiwlociiUna tenuis, Brady («o« Czjzek), 1884, FC, pi. x, fig. 10 (? also fig. 9). 

 Spiroloculina teiiuissima, Cushman {non Reuss), 1910, etc., FNP, 1917, p. 32. 

 } Spiroloculina tenuis, Sidebottom (nan Czjzek), 1918, FECA, p. 5. 

 Spiroloculina tenuissima, Cushman {non Reuss), 192 1, FP, p. 400, pi. Ixxxiv, fig. 2. 



Two stations: 386; WS 204. 



A single specimen at each station. 



Brady regarded the Spiroloculina tenuissima of Reuss (R 1867, FSW, p. 71, pi. i, 

 fig. 1 1) as synonymous with the Oiiinqiielocidina tenuis of Czjzek (C. 1848, FWB, p. 149, 

 pi. xiii, figs. 31-4), a view which has been generally accepted, as the figure of Reuss is 

 distinctly sigmoiline, and where either form is abundant a complete range of specimens 

 joining the two species can usually be obtained. But he was less happy in failing to 

 recognize that the test in both species is always more or less coated with arenaceous 

 investment and is never truly porcellanous. In his figures of Spiroloculina tenuis 

 (Czjzek) in the Challenger Report he includes one (possibly two) figures, which are 

 clearly porcellanous Spiroloculinae, from deep water in the Atlantic (Challenger St. 332, 

 2200 fathoms). He appears to have regarded them as pauperate or immature specimens. 

 In the text (B. 1884, FC, p. 152) he writes that "in small delicate specimens the test is 

 commonly Spiroloculine from beginning to end", but he nowhere refers to the nature 

 of the test. 



Subsequent authorities have followed Brady, with the result that the Httle porcel- 

 lanous species has not, so far as I am aware, been given a specific name. It is well 

 described by Cushman in his Pacific and Philippine monographs. His description is: 

 "Test very thin, translucent, elongate, compressed, in front view tapering towards 

 either end; chambers long and narrow, peripheral margin broadly rounded, chambers 

 in transverse section circular ; apertural end produced into an elongate neck, aperture 

 rounded, usually without distinct teeth ; wall smooth. Length usually less than 0-5 mm. " 



