NO. 1 OSBURN : EASTERN PACIFIC BRYOZOA — CHEILOSTOMATA 125 



half of the front surface, with 3 spines on its upper margin. Scutum 

 simple, often a mere spinous process, sometimes broadened at the ex- 

 tremity; spines and scuta distinctly jointed. Frontal avicularia few and 

 only on the axial zooecia below a bifurcation, large, raised, the beak 

 oblique or transverse. Lateral avicularia usually present, large. Ooecia 

 globose, smooth. (After Robertson.) 



Described by Robertson from the Pribilof Islands, Bering Sea (Kin- 

 caid collection), and recorded also from Homer, Unalaska, and Yakutat, 

 Alaska. O'Donoghue reported it as far south as Ucluelet, British Co- 

 lumbia. Not taken in the Hancock dredgings. 



P ^ Tricellaria praescuta new species 

 Plate 14, figs. 5 and 6 



Zoarium erect, dichotomous, branches stiff and not incurved ; inter- 

 nodes of 3 to 15 zooecia, the basal ones short; joint crossing bases of 

 both zooecia far below the opesia ; radicles developed only on the more 

 basal internodes. 



Zooecia closely set and uniform; axis of the branch a straight line; 

 zooecial length 0.40 mm (basal zooecia of a branch about 0.55 mm), 

 and the width of a branch also about 0.40 mm. The ovate opesia occupies 

 about half of the zooecial length, the mural rim narrow and little raised. 

 The arrangement of the spines is unusual (1) a broad scutum with a 

 stout pedicel, attached at the inner side on the proximal border, extends 

 diagonally upward to cover most of the proximal third of the opesia 

 (sometimes narrower but always stout) ; (2) at about the middle of the 

 opesia on each side there is a stout, hollow spine which is somewhat 

 scutiform (i.e., broader above its base) which curves upward and parti- 

 ally across the opesia, extending often beyond the aperture, occasionally 

 these spines are bifurcate at the tip; (3) a short, stout, hollow spine at 

 each distal angle (often an additional smaller spine on the outer angle) 

 directed forward. There are no frontal avicularia. Moderately large, ele- 

 vated marginal avicularia abundant, the rostrum and the triangular 

 mandible both hooked. The axial zooecia bear scuta and spines similar 

 to the others, with the addition of a short median terminal spine. 



Ooecia are present on all of the zooecia except on the bases of the 

 internodes and the axial zooecia; prominent but a little flattened on the 

 front, which bears irregularly radiating lines and a few conspicuous 

 pores ; about 0.20 mm broad and extending to the opesia of the succeed- 

 ing zooecium. 



There is a general resemblance to T. (Menipea) erecta Robertson, 

 but in erecta the ovicells are imperforate and the sculpturing is different, 



