Zooecia 



94 BULLETIN 125, XINITED STATES NATIONAL MUSEUM. 



Variations. — The ordinary zooecia and the ovicelled zooecia develop on the 

 same plane. The male zooecia have no fixed place and lap over very often on the 

 others; when they are numerous and erect they give to the zoarium an aspect of 

 Cellepora, which explains its generic name of Celleporella given by certain authors. 

 The presence of three sorts of zooecia renders this species easy to determine; 

 however, it is not rare to find zoaria uniquely formed of ordinary zooecia, in which 

 case the determination is more difficult. 



This species generally lives on algae and the depths indicated by the dredgings 

 gives only information of secondary importance when the substratum is unknown. 

 This is a species of the cold boreal zone and it never goes farther south than the 

 forty-second parallel. We have found in the Pliocene of Monroe County, Florida, a 

 mediocre specimen of a very closely related species. We will only give it a name 

 if we have the chance to find better specimens. Generally its niicrometric measure- 

 ments are more reduced. 



Measurements. — Ordinary zooecia: Apertura , ~' 



•' ^ i Za = 0.08 mm. 



fL2 = 0.30mm. 

 1 l2 = 0.20 mm. 



TVT 1 • A 1 fAa = 0.04mm. 



Male zooecia: Apertura , „^, 



^ I to = 0.04 mm. 



Zooecia! t = ^-;6-0-20 mm. 

 [ (2 = 0.12 mm. 



Occurrence. — Pleistocene: Santa Barbara (rare); Dead Man's Island off San 

 Pedro (rare); Los Angeles and Santa Monica, California (rare). 



Geological distribution. — Plaisancian of England (Busk). 



Hahitat.— Arctic Ocean: Iceland (162 meters); Franz Joseph Land (12-150 

 meters); Barents Sea (106 meters); Jean Mayen; Spitzberg; Greenland (4-48 

 meters) ; Sea of Kara; Nova Zembla (3-32 meters). North Sea: Norway; Germany; 

 Denmark (8-27 meters). Eastern Atlantic: Off England, English Channel, Gulf 

 of Gascony. Western Atlantic: Labrador, Woods Hole region. Eastern Pacific: 

 Alaska, California. 



Plesioty pes. —Ca,t. Nos. 68531, 68532, U.S.N.M. 



raPPOTHOA HVALINA. var. RUGOSA, new variety. 



Plate 35, fig. 9. 



Only the figured specimen has been found; it perhaps forms a distinct species. 

 The large transverse wrinkles of the frontal are very characteristic. The species 

 differ from Hippothoa bougainvillei D'Orbigny, 1839, in the absence of two laro-e 

 frontal beaks. * 



Occurrence.— Pleistocene: Santa Barbara, California (very rare). 

 Holotype. —C&t. No. 68533,U.S.N.M. 



