4o8 DISCOVERY REPORTS 



Patellinoides we take to be intermediate between SpirilUno and PoteUina. The latter 

 genus is obviously a derivative of Spirillina, and the proloculum is normally followed by 

 a simple unseptate tube which may attain to as many as four convolutions before the 

 secondary septa begin to form. But we take the view that Patellinoides is probably not 

 on the line of evolution between Spirillina and Patellina, but is more likely to be a 

 degeneration from the latter genus, in which the alternate plan of growth has been pre- 

 serv^ed and the secondary septa have been abandoned. This theory is perhaps best 

 supported by the fact that balsam-mounted specimens under high magnification some- 

 times show a line of minute beads round the peripheral edge of some of the chambers, 

 which beads may represent vestigial septa. 



Patellina campanaeformis , Brady, should on the diagnosis of Brady be transferred to 

 Patellinoides . But it is quite possible that it represents yet another separate and unde- 

 scribed genus. It is unlike either of our species, and nothing is known of the organism 

 beyond what Brady has written. 



328. Patellinoides conica, sp.n. (Plate XIII, figs. 26-29). 

 Three stations: WS 88, 92, 408. 



Test conical, oval in plan, high-domed, the proloculum and spiral tube being 

 followed by a succession of alternate, undivided chambers, up to five to six pairs, which 

 are placed somewhat diagonally across the long axis of the oval base. Sutural lines distinct 

 but flush. The minute dots which, when viewed under a high power, are seen to be 

 scattered round the lower peripheral edge of the chambers are apparently solid pillars 

 of shell substance inside the chambers. Seen through the glassy shell they have the 

 appearance of a line of pores. 



Average length, 0-20 mm.; breadth, 0-13 mm.; height, 0-05 mm. 



P. conica occurs at WS 408 at 454 m. It is rare, but many specimens were found. 

 Very rare at the other stations. It appears to be identical with specimens in our cabinet 

 from Plymouth, and from the Faroe Channel, and the species is therefore probably of 

 very wide distribution. The British specimens are larger than those from the Falklands, 

 and the peripheral pores are more distinct, but they show no evidence of the definite 

 septation proper to Patellina. 



329. Patellinoides depressa, sp.n. (Plate XIII, figs. 30-33). 

 Four stations: 388; WS 88, 245, 408. 



Test free, a long oval in plan, conical, but very depressed or scale-like, consisting of a 

 proloculum followed by a short simple tube, then by unseptate chambers arranged 

 alternately to the number of 3-5 pairs. Each chamber surrounded by a carina which 

 persists in the form of strongly limbate sutural lines. Texture hyaline. 



Length, up to 0-40 mm.; breadth, 0-25 mm.; height, 0-04 mm. 



Very rare, but a good many specimens have been found, principally at 388 and WS 88. 

 They appear to be identical with two specimens in our cabinet from the Faroe- Shetland 

 Channel at 128 m., and the species may therefore have a very wide distribution. 



