NO. 2 OSBURN: eastern pacific BRYOZOA — CHEILOSTOMATA 447 



cularia are rare, similar to the oval frontal ones but usually larger. 

 Pores are also often wanting on the dorsal kenozooecia, but occasionally 

 as many as 2 are present. The large infrafenestral avicularium figured 

 by Harmer (text fig. 33) is rare; the mandible has the same form as in 

 the figure, with 3 or 4 points. Occasionally there are small frontal 

 zooeciules bearing oval avicularia. 



The ovicell is pyriform, smooth and glossy, with an elongate median 

 fissure which remains open; the labellum is well developed, elongate 

 v-shaped with a rounded point, the lateral flanges narrow and extending 

 beyond the tip of the labellum. 



This variety differs from denticulata Busk in the consistently nar- 

 rower branches (very regularly 3 series of zooecia, never more than 4), 

 in the absence of any fused branches or connecting trabeculae and in 

 the comparatively rare avicularia. Otherwise it conforms to the descrip- 

 tion of denticulata. While Harmer ( 1934:582) indicates that the width 

 of the branches ranges from 2 to 9 zooecial series, the consistently nar- 

 row branches of our 24 specimens, distributed from the Galapagos 

 Islands to Costa Rica, makes it seem advisable to apply a varietal name 

 to this form from the Eastern Pacific region. R. denticulata has been 

 recorded from the Sandwich Islands (the type locality), from Japan 

 and other localities in the western Pacific and across the Indian Ocean 

 to East Africa. 



Type, AHF no. 97. 



Type locality, Hancock Station 455, Albemarle Island, Galapagos, 

 0°55'00"S, 90°30'00''W, 70 fms. Other Hancock Stations, 143-34, 

 Wenman Island; 173-34, South Seymour Island; 324-35, Albemarle 

 Island; 788-38, Daphne Major Island; 466, James Island, Galapagos; 

 and 324, Salinas Bay and 328, Cocos Island, Costa Rica, 5 to 150 fms. 



Genus PHIDOLOPORA Gabb and Horn, 1862 



The description of the genus by Gabb and Horn (1862:138) is so 

 brief as to be worthless, but as it is based on their new species, P. labiata, 

 the description and figure of which are clear, it must be accepted. 



Canu and Bassler (1923:154) give the following description: "The 

 frontal of the ovicell is not fissured. The aperture is semilunar, with a 

 concave proximal border. The peristomice bears a rimule spiramen. The 

 frontal is an olocyst. No labial avicularium." Genotype, Phidolopora 

 labiata Gabb and Horn, 1862. 



