NO. 3 OSBURN : EASTERN PACIFIC BRYOZOA CYCLOSTOMATA 635 



much attention has been given to the shape of the ovicells by Canu and 

 Bassler it is important to note the amount of variation in form. 



Jullien described the species from the Grand Bank of Newfoundland, 

 at 155 meters. The only other positive reference is that in Osburn's 

 report on dredgings by Captain R. A. Bartlett in Baffin Bay, three 

 colonies w^ith ovicells, (previously unknovi^n), at 140 to 210 feet. It is 

 probable that Smitt's Mesenteripora meandrina in the Torell collection 

 from Greenland (1866:432) should now be referred to gnmaldit rather 

 than to the fossil Diastopora meandrina of Wood. 



Point Barrow, Alaska, Alaska Research Laboratory, at 217 feet, G. E. 

 MacGinitie, collector, several fragments agreeing with Baffin Bay speci- 

 mens in all other details but without ovicells. The range of distribution 

 is evidently high northern and probably circumpolar. 



Plagioecia meandrina (Canu and Bassler), 1930 

 Plate 66, figs. 6 and 7 



Diaperoecia meandrina Canu and Bassler, 1930:51. 



The zoarium has a very striking appearance, consisting of a broad 

 encrusting base from which arise at intervals narrower bilaminate 

 branches or fronds which often anastomose to form large quadrangular, 

 pentagonal or hexagonal fenestrae. The branches are usually at right 

 angles to the plane of the zoarium. On the encrusting base the zooecia 

 are arranged in quincunx, but on the erect branches they tend to run 

 in rather regular series more or less transverse to the branch; they are 

 not connate but well separated. The peristomes of the base are short 

 but on the branches, especially near the growing edge, they are mod- 

 erately elongate and nearly erect. The basal lamina of the base extends 

 rather broadly beyond the functional zooecia and on the branches there 

 is a similar but much narrower lamina projecting from between the two 

 zooecial layers on one edge of the branch. The zooecial tubules are very 

 little inflated and their outlines are often obscure. The peristomial 

 apertures are round and about 0.10 mm in diameter. 



The ovicell is a distinct inflation, irregularly elliptical, transverse and 

 parallel to the edge of the branch and surrounding a number of the 

 peristomes, most of which are closed, like those of P. patina, with a 

 calcified membrane in the middle of which is a minute tubule. The 

 ooeciostome is small, short, nearly erect, situated near the middle and 

 terminal, free between the peristomes, and measures 0.08 mm. 



