NO. 1 OSBURN : EASTERN PACIFIC BRYOZOA — CHEILOSTOMATA 25 



species, "at Monterey, California, it occurs free, very much folded and 

 contorted foliaceous masses," and it seems probable that these specimens 

 were perfragilis. 



A remarkable colony, shaped like a large pompon, was collected in 

 shallow water at San Pedro, California. The zoarium measures about 

 140 mm in length by 100 mm in width and height, and is remarkably 

 convoluted. It is attached to a large pebble, the encrusting base being 

 more than half as wide as the erect portion and spreading down over 

 the sides of the pebble. The specimen is deposited in the Cabrillo Beach 

 Marine Museum of the City of Los Angeles and the author is indebted 

 to Dr. W. L. Lloyd, Director of the Museum, for the privilege of study- 

 ing the specimen. Some fragments of the zoarium are deposited in the 

 Hancock collections. 



Membranipora fusca new species 

 Plate 1, fig. 14 



Zoarium encrusting on shells and stones, covering considerable areas ; 

 at first the thick ectocyst is clear, then the operculum develops a heavy 

 dark border and later the whole ectocyst becomes yellowish brown, then 

 darker to nearly black. 



The zooecia are moderate in size, usually ranging between 0.50 and 

 0.70 mm in length and 0.30 to 0.45 mm in width, the opesia occupying 

 nearly all of the front; a narrow brown line separates the zooecia even 

 in younger stages. The descending cryptocyst is broadest at the proximal 

 end and continues more narrowly along the sides, finely granulated and 

 without spinules. The basal gymnocyst is only wide enough to bear a 

 pair of transversely elongate low tubercles, which in final calcification 

 may fuse in the midline or become heavy rounded knobs. The operculum 

 is semicircular, about 0.20 mm in width, heavily chitinized like the frontal 

 ectocyst and with a conspicuous black border. Multiporous septulae are 

 present in both the lateral and distal walls. No spines nor avicularia and 

 no ovicells. 



Type, AHF, no. 9. 



Type locality, Mussel Point, northern California, 36°37'20'' N, 121° 

 54'15"W. Also at Del Monte, California, 36°37'00"N, 121°53'00''W, 

 intertidal to 6 fms, collected by Miss A. E. Blagg and Dr. R. L. Bolin, 

 numerous colonies; also at Tomales Bay, California, 5 fms (Osburn). 



