278 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 



Hippothoa divaricata Lamouroux, 1821 

 Plate 30, fig. 6 



Hippothoa divaricata Lamouroux, 1821 :22. 

 Hippothoa divaricatOj Hincks, 1880:289. 

 Hippothoa divaricata, Robertson, 1908 :296. 

 Hippothoa divaricata, O'Donoghue, 1923 :38 ; 1926 :53. 



The zoarium is uniserial, branched, encrusting pebbles and shells. 

 The zooecia have a short basal, tubular portion, usually considerably 

 less than the length of the expanded portion, and in the variety conferta 

 Hincks the basal portion is almost wanting. The zooecial body is elongate- 

 ovate, inflated, the front usually with a low carina, and there is never 

 more than a slight expansion of the dorsal side for attachment. The 

 aperture is rounded with a distinct sinus in the proximal border. 



The ovicell is smooth and globular with a small rounded umbo on 

 the top, borne on a slightly reduced zooecium. 



Widely distributed around the world. Hincks and the O'Donoghues 

 listed it from a number of localities in British Columbia and Robertson 

 collected it at several localities on the California coast. Hincks, 1880:289, 

 lists it from Mazatlan, Mexico. 



In the Hancock collections it was found to range southward from 

 southern California to Mexico, the Gulf of California, Costa Rica, 

 Panama, and the Galapagos Islands. Also common at Point Barrow, 

 Alaska, G. E. MacGinitie, collector, Alaska Research Laboratory. 



Hippothoa flagellum Manzoni, 1870 

 Plate 30, figs. 7-8 



Hippothoa flagellum Manzoni, 1870 :6. 

 Hippothoa flagellum Hincks, 1880:293. 



This is a more delicate species than others of the genus, with a basal 

 tubular portion often several times as long as the expanded zooecial 

 body. The latter is elongate ovate, without dorsal expansion ; the aperture 

 ovate instead of rounded and with a sinus in the proximal border. The 

 ooecia are borne on short, reduced individuals which are usually on short 

 tubular stalks at the sides of normal zooecia. 



Distributed around the world in warmer and temperate seas. 



In the Hancock collections this species was found to be well dis- 

 tributed along the Pacific coast from Mexico (Guadalupe Island and 

 the Gulf of California) to Panama, Colombia, Peru and the Galapagos 

 Islands, from shallow water down to 100 fms. 



