NO. 2 OSBURN: eastern pacific BRYOZOA — CHEILOSTOMATA 451 



Schizotheca fissurella (Hincks), 1882 

 Plate 55, fig. 5 



Schizoporella fissurella Hincks, 1882:253. 

 Schizotheca fissurella, Hincks, 1884:21. 



Hincks described this species from "Dolomite Narrows; Cumshewa, 

 etc. ; not uncommon on shells and stone." British Columbia. It has 

 not been recorded since and a brief digest of Hincks' description follows : 

 Zoarium encrusting. Zooecia small, ovate, the oral region raised, sub- 

 erect. Orifice (primary aperture) arched above, straight below, with a 

 narrow slit-like sinus ; peristome thickened and elevated, notched in 

 the center and bimucronate ; on each side a sharp spinous process, often 

 wanting. Ooecium rounded and smooth, with a small longitudinal fissure 

 above the opening, and a central tooth (labellum) just within the oral 

 arch. Spines? 



Our one specimen agrees well with the above description, but Hincks 

 did not mention the avicularia which in our specimen are moderately 

 large, with pointed mandible, located on the front proximal to the 

 peristome and oriented more or less proximally. Also he did not note the 

 beaded vestibular arch, which is a common feature of the family. In spite 

 of these additions our specimen fits the description so well that I have 

 little hesitation in placing it under fissurella. 



Hancock Station 2160, one mile south of San Benito Island, west 

 of southern California, 28°17'15"N, 115°35'40"W, 44 fms. 



Schizotheca umbonata new species 

 Plate 55, fig. 4 



Zoarium encrusting, the surface very rough with stout, high umbos. 

 The zooecia are moderate in size, 0.40 to 0.50 mm long by 0.30 to 

 0.40 mm wide, but very deep; the frontal in young marginal zooecia 

 is highly arched and smooth, but almost immediately becomes very heavy 

 with the development of a large, high pointed umbo. The base of the 

 umbo is semilunate, partially encircles the proximal end of the aperture, 

 extends nearly the full width of the zooecium, and covers one-third to 

 one-half of the frontal surface ; it usually rises into a single tall medium 

 process, but may present two or rarely three points. The primary aper- 

 ture is so deeply immersed that its character is visible only on marginal 

 zooecia ; it is somewhat more than a semicircle, straight on the proximal 

 border, with a small, deep rounded sinus; the vestibular arch is beaded. 

 Small avicularia with pointed mandible are irregularly distributed. 

 Dietellae are present. 



