42 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 



as a zooecium, but much narrower, only 0.26 to 0.30 mm in width; its 

 opesia is elh'ptical and partially divided near its middle, the border of the 

 proximal portion minutely crenate. The mandible is very elongate, usually 

 about 1 mm, the rachis slender and without denticles, strongly curved 

 downward near the tip, the base is triangular, about 0.20 mm wide, and 

 is hinged to the frontal surface of the chamber; the rachis is winged 

 equally on both sides, continuing nearly to the curved tip. 



The ovicell is high and prominent, transverse, 0.35 to 0.40 mm wide 

 by 0.20 mm long, endozooecial and closed by a special membrane, occa- 

 sionally there is a small tuberosity on the top. 



Dietellae are present in the lateral walls and multiporous septulae in 

 the distal wall. 



O'Donoghue described the species under Membranipora and changed 

 it later to Callopora. However, the ooecia are definitely endozooecial, as 

 shown by dissection, and the species is here transferred to the genus 

 Hincksina. Recorded from off Protection Gap and Schooner Bay, British 

 Columbia, down to 30 fathoms. 



In the Hancock collections there are several colonies on a shell labelled 

 "local," but without further data. Also off Santa Catalina Island, south- 

 em California, on a brachiopod shell. 



<?/ Hincksina nigrans (Hincks), 1882 

 Plate 5, fig. 5 



Membranipora nigrans Hincks, 1882 :248. 

 Membranipora macilenta }\x\\\en, 1802:25. 

 Membranipora macilenta. Waters, 1900 :61. 

 Callopora nigrans, Osburn, 1919 :608 ; 1923 :8 ; 1932 :8. 

 Adenifera nigrans, Canu and Bassler, 1920 :102. 



Zoarium encrusting, coarse, light brown to nearly black. The zooecia 

 are large, 0.70 to 1.00 mm long by 0.45 to 0.55 mm wide; distinct; 

 mural rim raised and granulated, the distal wall arched forward and 

 its rim somewhat elevated; opesia occupying nearly all of the front; 

 gymnocyst vestigial; cryptocyst sometimes forming a narrow proximal 

 shelf, but often not evident. Large multiporous septules are present, usu- 

 ally two in the distal wall and the same in each half of the lateral wall, 

 but more rarely some uniporous septulae are found. Small lateral avicu- 

 laria are present on practically all of the zooecia, one on each side opposite 

 the distal end of the operculum, the rostrum elevated and the triangular 

 mandible directed backward. No spines. 



