NO. 1 OSBURN : EASTERN PACIFIC BRYOZOA CHEILOSTOMATA 69 



Ovicell prominent, rounded, smooth with a transverse rib, width 

 about 0.25 mm. 



This species has some resemblance to C. craticula, but Hincks ( 1889 : 

 46) has indicated the differences: M. lineata differs in the larger size, 

 the less regular arrangement of the zooecia, the spines rounded and much 

 less recumbent. 



It is a common Atlantic species, on the American coast from Cape 

 Cod to Greenland and Osburn has recorded it as far west in the Arctic 

 Ocean as Bernard Harbor, Northwest Territory (about 115 degrees W). 

 O'Donoghue lists it at a number of localities in British Columbia. 



Hancock Station 1662-48, Santa Cruz Island, southern California. 

 Specimens also from Dillon Beach, California, Menzies, collector, and 

 Nunivak Island, Alaska. It does not appear to be a common species on 

 the Pacific coast. 



Callopora horrida (Hincks), 1880a 

 Plate 6, fig. 9 



Membranipora horrida Hincks, 1880a:82; 1884:7. 

 Membranipora calif orniensis Waters, 1898 :681. 

 Membranipora horrida, Robertson, 1908 :260. 

 Membranipora horrida, O'Donoghue, 1923 :24. 

 Callopora horrida, O'Donoghut, 1925:97; 1926:33. 



Zoarium encrusting shells, stones, sponges, etc. Zooecia ovate, very 

 distinct with wide grooves; opesia more or less ovate, the mural rim 

 thick, elevated and slightly crenate. Dietellae in the lateral and distal 

 walls. Two or three pairs of stout erect distal spines and the same num- 

 ber of lateral ones which are smaller, sharp-pointed and curved over 

 the opesia. A large avicularium is located on the basal gymnocyst, its 

 long pointed mandible, which is often curved laterally, directed forward 

 to one side of the opesia; occasionally smaller avicularia of similar form 

 are present in the same position. 



Ooecium rather small, globular, with a transverse rib near its aper- 

 ture ; the avicularium of the distal zooecium is often attached partly to 

 the ooecium, but does not cover it as in the genus Tegella. 



There is much variation in the number and size of the spines and in 

 the width of the separating grooves. 



Hincks described this species from California, as did Waters his cali- 

 forniensis. Robertson listed it from Puget Sound southward to Pacific 

 Grove, California. O'Donoghue recorded it from numerous localities, 

 Puget Sound northward in British Columbia. 



