NO. 2 OSBURN: EASTERN PACIFIC BRYOZOA — CHEILOSTOMATA 475 



Type, AHF no. 103. 



Type locality, Hancock Station 1257-41, three miles NW of Nativ- 

 idad Island, Lower California, 27°55'53''N, 115°iy58''W, 31 fms. 

 Also dredged at Station 1051, ofif San Miguel Island, 12 to 19 fms; 

 1662-48, Santa Cruz Island, 23 fms; Palos Verdes (Accession 1212) 3 

 to 5 fms on an abalone shell ; and a part of Robertson's Schizoporella 

 areolata (non Busk) from Santa Catalina Island, all from southern 

 California. 



Genus HIPPALIOSINA Canu, 1918 



Ovicell endozooecial. The aperture is elongate, elliptical, divided 

 into two parts by triangular cardelles ; the poster smaller than the anter. 

 Frontal a granular pleurocyst with areolar pores which are sometimes 

 in more than one row. Usually a small avicularium at each side of the 

 aperture. Genotype, Escharella rostrigera Smitt, 1873. 



Hippaliosina rostrigera (Smitt), 1873 

 Plate 56, fig. 9 



Escharella rostrigera Smitt, 1873 :57. 

 Lepralia rostrigera, Osburn, 1914 :21 1. 

 Hippaliosina rostrigera, Canu and Bassler, 1928:130. 

 Hippaliosina rostrigera, Hastings, 1930:729. 

 Hippaliosina rostrigera, Osburn, 1940:448. 



Zoarium encrusting. Zooecia of moderate size but very variable, 

 ranging from 0.30 to 0.60 mm in length by 0.25 to 0.35 mm in width ; 

 the frontal a granular pleurocyst with a row (sometimes two rows) of 

 areolar pores, nearly flat. The aperture is variable in form, longer than 

 broad, the anter more than a semicircle and separated from the poster 

 by strong, pointed cardelles ; the poster usually narrower than the anter 

 and with an arcuate proximal border. The peristome is thin and slightly 

 raised only around the distal border. No spines. There is usually a small 

 avicularium on either side of the aperture, the mandible short or long 

 and directed forward and inward around the border. 



The endozooecial ovicell is scarcely noticeable on the surface but 

 the fertile zooecia are easily distinguished by their short, wide apertures. 



Described from the Gulf of Mexico and known only from the West 

 Indian region until Hastings recorded it from Gorgona, Colombia. 



Hancock Stations: 154-34, Albemarle Island, Galapagos; 332, Bahia 

 Honda, Panama; and 270, east of Angel de la Guardia Island, Gulf 

 of California. Shore to 27 fms. 



