NO. 1 OSBURN: eastern pacific BRYOZOA — CHEILOSTOMATA 149 



proximal corner and the short diagonal groove on the inner side. The 

 seta is weak and not longer than two zooecia. There is a single axial 

 vibraculum, of the same size and general form as the lateral ones, but 

 more rounded proximally. 



The ooecium is large, extending to the opesia of the distal zooecium, 

 usually somewhat longer than wide, with a regular row of rather large 

 pores around the base and a number of smaller ones scattered over the 

 upper surface. These are connected by radiating lines and are not tubular. 



Type, AHF no. 40. 



Type locality, Station 795-38, Sulivan Bay, James Island, Galapagos 

 Islands, 0°16'12''S, 90°34'50''W, 36 to 40 fms, one colony about 25 mm 

 in height. Also taken at Sta. 450, Galapagos, 0°55'00''S, 90°30'00''W, 

 60 fms, and 451, Post Office Bay, Charles Island, Galapagos, 100 fms. 



Scrupocellaria varians Hincks, 1882 

 Plates 19, fig. 5, and 20, fig. 6 



Scrupocellaria varians Hincks, 1882:461. 



Scrupocellaria variaiis, Robertson, 1905:260. 



Scrupocellaria varians, O'Donoghut, 1923:18; 1926:41 ; 1925a:98. 



Zoarium much branched and bushy, seldom as much as 20 mm in 

 height ; the internodes consisting of from 3 to 6 zooecia in a series ; the 

 joint crosses the outer zooecium proximal to the opesia. 



Zooecia comparatively long and slender, 0.35 to 0.55 mm by 0.18 to 

 0.20 mm, narrowed to about 0.13 mm at the proximal end, the outer 

 margin nearly straight. The long ovate opesia occupies about half of the 

 frontal length, the cryptocyst moderately developed. The scutum is small 

 and quite variable; usually it is three-pronged, but it ranges all the way 

 from a simple curved spine to six points ; it covers only a small portion 

 of the opesia. There are two or three small outer and one inner spines. 



Frontal avicularia are present on most of the zooecia, just proximal 

 to the opesia, somewhat elevated, with a triangular mandible which is 

 oriented laterally. The lateral avicularia are of two kinds, the usual 

 form with a triangular mandible ; and giant avicularia 0.30 to 0.40 mm 

 in length, with a trough-like rostrum which varies in the form of the 

 tip from rounded to three-pointed ; mandible with a strongly hooked tip. 

 Hincks' description indicates that the giant avicularia are "much the 

 more abundant," but there is great variation and in some of our speci- 

 mens the giant form is comparatively rare. 



The vibracular chamber is very short, somewhat triangular in form, 

 not visible from a frontal view; the groove is transverse and the seta 

 weak and usually not longer than a zooecium. The radicle chamber is 



