472 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 



leaves a large clear space on each side beyond the cardelles (the extent 

 of this axial band quite variable). A thick ectocyst which varies from 

 brovv^nish to nearly black in color. Genotype, Lepralia cucullata Busk, 

 1854:81. 



Watersipora cucullata (Busk), 1854 

 Plate 56, figs. 1-5 



Lepralia cucullata Busk, 1854 :81. 



Lepralia atrofusca Busk, 1856:178. 



Schizoporella atrofusca and var. labiosa Hincks, 1886:269. 



Lepralia? cucullata. Waters, 1909:150 (excellent bibliography). 



Pachycleithonia nigra Canu and Bassler, 1930:25. 



Watersipora cucullata, Hastings, 1930:729. 



Watersipora cucullata, Marcus, 1937:118. 



Watersipora cucullata, Osburn, 1940 :449 ; 1947 :40. 



Zoarium encrusting, occasionally rising into low frills, conspicuous 

 because of its color, brownish-purple to black. Zooecia large but varying 

 greatly in size, average length about 1.00 mm, width about 0.40 mm, 

 rather regular in form and quite distinct. The front is regularly rounded 

 from side to side, a smooth tremocyst with numerous large pores ; chalky 

 white beneath the thick, pigmented ectocyst. The primary aperture is 

 large and varies in its proportions ; typically the poster is more or less 

 semicircular, but it may be broadly arcuate; the condyles are usually 

 strong and conspicuous ; just above each condyle there is usually a small 

 cup-shaped indentation of the border of the aperture. The operculum 

 has the form of the aperture, heavily pigmented like the front, some- 

 times with a rounded clearer area on either side in advance of the con- 

 dyles, usually with a black sclerite extending straight forward from the 

 point of attachment on either side ; an unusual feature of the operculum 

 is the presence of a small shining tubercle on each side proximal to the 

 condyles. The peristome is typically simple and slightly elevated, but 

 it may rise into erect lappets or folds on its proximal border (var. 

 labiosa), or extend forward in a flat shelf above the poster (var. nigra). 

 No spines, no avicularia. As Hastings (1930:730) indicates, there is 

 much variation even on the same zoarium, and about the only invariable 

 character I have been able to note is the presence of the minute shining 

 tubercles on the operculum behind the condyles. 



There is no evidence of an ovicell externally, and Waters ( 1909 :151 ) 

 has shown that the larva develops in a sac at the distal end of the zooecial 

 chamber. 



