NO. 1 OSBURN : EASTERN PACIFIC BRYOZOA — CHEILOSTOMATA 103 



Genus VELUM ELLA Canu and Bassler, 1917 

 "The retractor muscles of the polypide are attached in the median 

 axis of the zooecium; the opesiular indentations are symmetrical. The 

 onychocellaria are straight, without distal canal ; the rachis of the mandi- 

 ble bears two broad membranes; the opesium of the onychocellarium is 

 elliptical and entirely denticulated" (C. and B.) Genotype, Onychocella 

 levinseni Canu and Bassler, 1917. 



Velumella americana Canu and Bassler, 1928 

 Plate 12, figs. 7 and 8 

 Velumella americana Canu and Bassler, 1928 :54. 

 Vincularia abyssicola Smitt, 1873 :6 (part, fig. 60, not 61 ) . 

 Smittipora aby ssico la, Oshurn, 1914:195; 1927:125. 

 Velumella americana, Osburn, 1947 :17. 



Zoarium encrusting, yellowish to light brown in color. Zooecia rather 

 large, 0.70 to 0.80 mm long by about 0.45 mm wide, distinct with a deep 

 furrow; mural rim thin and somewhat elevated; cryptocyst depressed, 

 smooth in younger stages, becoming granulated with age. The opesia is 

 moderately large, measuring about 0.25 mm in either dimension, the 

 proximal border more or less straight, the opesiular indentations distinct. 

 The onychocellarium is about as long as the zooecia, but usually nar- 

 rower; its opesia is long oval, narrower proximally and crenulate; the 

 mandible is long, 0.60 to 0.65 mm, curved at the tip, and with two 

 membranous wings which together form an oval with the point forward ; 

 the base of the rachis is broad, 0.20 mm, triangular and bears a triangu- 

 lar lucida. Ovicell small and endozooecial, not conspicuous. 



The species is common and well distributed in the West Indian re- 

 gion. Our Pacific specimens do not seem to differ, except in the heavier 

 granulation of the cryptocyst. 



Hancock Stations: 170-34 and 401, Chatham Island, Galapagos, 17 

 to 32 fms. Also Gulf of Panama, Galtsoff collection, on pearl oysters. 



Genus CALESGHARA MacGillivray, 1880 

 This genus has been redefined by Harmer (1926:221) as follows: 

 "Frontal membrane occupying the entire surface, the operculum small 

 and Membraniporine. Spines wanting. Cryptocyst extensive, imperforate, 

 tuberculate, its proximal part produced into a Steganoporelliform median 

 process, free distally or uniting with the lateral cryptocyst. Opesia tri- 

 foliate, or opesiules complete, according to the character of the median 



