402 MEMOIRS OF THE UNIVERSITY OP CALIFORNIA 



Earlier records of its occurrence are as follows: Ouljanin (1868) ; Biitsclili 

 (1873) off the coast of Norway; Bergh (ISSlb) from the Baltic off the coast 

 of Demnark in July; Pouchet (1883, 1885, 1887) from the Atlantic off Con- 

 carneau, France, April to July, and in the Arctic near Iceland in Angust; 

 Lauterl)orn (1893) from the North Sea off Helgoland, Germany; Anrivillius 

 (1896) from the Baltic at Kiel, Germany, (1898) from the Skagerack in Jan- 

 uary and Septemljer to November; Jorgensen (1899) off the west coast of 

 Norway at Hjeltef jord in May, at Puddef jord in November and December, and 

 (1912) from the Skagerack in September, November, and December; Pavillard 

 (1905) from the Mediterranean at Etang de Thau near Cette, France, in October 

 and April ; Ostenf eld (1906, 1909, 1913) from the North Sea, August, November, 

 the Skagerack and Cattegat in November; Lolmiann (1908) from the Baltic at 

 Kiel, Germany, in April, ]\Iay, and September; and Lebour (1917&) at Ply- 

 mouth Sound, England, from May throughout the summer. It is thus seen to 

 be somewhat cosmopolitan in its habitat. 



CoMPARisoxs. — This s^Decies differs from P. kofoidi mainly in the lack of 

 ridges on the surface of the h^'poeone and in the lack of displacement of the 

 girdle. In P. kofoidi the girdle has a displacement of about 0.15 transdiameter. 

 The length of the latter species appears to be somewhat greater than that of 

 P. scliicartzi. 



Synonymy. — This organism was described by Biitschli (1873) as P. 

 scliwartzi. Bergh (1881?^) described a second species as P. auricidaria, which 

 Kofoid (1907?>) later reduced to a synonym of Biitschli 's species, P. schwartzi, 

 critical examination of the two forms failing to reveal distinct specific differ- 

 ences. The form figured by Kofoid was separated by Chatton (1914r) from 

 P. scliwartzi and given specific status as P. kofoidi. 



