250 PROCEEDINGS OF THE ACADEMY OF [Vol. LXXV 



and flanges arranged as a comparatively simple fold on one side 

 and two much more complex, often hollow folds on the opposite 

 side. 



Known from the type only, an incomplete specimen 23 mm. 

 long, (gills 6.2 mm. thorax 4 mm.), diameter of thorax 2 mm. 



Station 4417, off Santa Barbara Island, 29 fathoms, fine yellow 

 sand and coralline rock. 



Spirorbis rugatus Bush. 



Several tubes attached to the tubes of large serpulids and Spio- 

 chcetopterus along with a few tubes of Hyalopomotopsis and bryo- 

 zoans, and to hydroid stocks with barnacles. Most of the tubes 

 are coiled flat but some of those associated with bryozoans are 

 elevated. The operculum agrees with Miss Bush's figure but the 

 collar setae are toothed rather than scalloped. 



Stations 4454, off Point Pinos Lighthouse, 65-71 fathoms, green 

 mud, gravel and sand; 4555, same locality, 66-69 fathoms, green 

 mud and rocks. 



Filograna tribranchiata sp. no v. 



The largest specimens, including the type, measure nearly 5 

 mm. in length, of which the branchiae are 1.3 mm., thorax 1.2 

 mm., and abdomen (including the unsegmepted region) 2.4 mm. 

 Setigerous thoracic segments 8, abdominal 24 to 26. 



Gills three pairs, poorly preserved, but apparently only one, 

 the right dorsal, usually bearing a spoon-shaped operculum at 

 the end of the radiole. Barbs few, short and macerated. Collar 

 and mantle appear to be typical though, probably as a result of 

 maceration, no lateral notches can be detected. 



First setigerous somite much longer than the other thoracic 

 somites which are about one-half as long as wide. Following the 

 thorax is a region of about one-half of its length in which no seg- 

 ments or setae can be distinguished and then the segmented abdo- 

 men, in which the segments become rapidly short and crowded, 

 terminating in a short bifid pygidium. 



Collar setae are in two series of five or six each. The dorsalmost 

 are simple, tapered and delicate, the ventral much larger, with a 

 prominent, coarsely toothed basal fin separated by a wide notch 

 from a tapering finely toothed distal limbus. Those of remaining 

 thoracic segments are also in two series of about four each, those 

 of one series like the dorsal collar setae, those of the other similar 

 in form but larger. The anterior third of the abdomen bears no 

 setae, the segmented portion at first single setae, then tufts of two 

 and finally at the caudal end of three. Abdominal setae are all of 

 one kind, perfect!}^ simple, slender, curved, capillary, finally be- 



