456 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 



The ovicell (0.25 mm wide, 0.20 to 0.25 mm long) is very thick- 

 walled, the surface smooth and glossy except in extreme calcification, 

 the frontal endooecial area nearly semicircular with a broad, short 

 labellum. 



There is some doubt as to the identity of this form with R. bispinosum 

 (Johnston). It has the smooth, non-costate frontal and the pair of 

 widely separated oral spines of that species. Hincks (1880: plate 40) 

 shows a large uncinate process on figure 1, but not on figs. 2, 3 and 

 4 ; this process is never large on our specimens. He also describes a large 

 avicularium (suboral), but his figures show it to be small in comparison 

 with some other species of the genus and both the chamber and mandible 

 appear similar in size to those in our specimens. The operculum is 

 similar to that figured by Hastings (1930, plate 14, fig. 91). O'Don- 

 oghue gives no description of his British Columbia specimens from 

 Northumberland Channel, and otherwise the species is not known 

 except from the British Isles and western Europe. 



In the Hancock Collections there are two specimens labelled "Tuan 

 Island, Pavlof Bay, Alaska, July 25, 1937," with no other data. 



Rhynchozoon rostratum (Busk), 1856 

 Plate 54, figs. 1-3 



Lepralia rostrata Busk, 1856 : 178. 



Cellepora verruculata Smitt, 1873:50. 



Cellepora verruculata, Osburn, 1914:214. 



Rhynchozoon verruculatum, Canu and Bassler, 1923:157; 1928a :31. 



Rhynchozoon rostratum, Hastings, 1930:728. 



Rhynchozoon verruculatum, Marcus, 1939:153. 



Rhynchozoon verruculatum, Oshurn, 1940:444. 



(References to R. verruculatum from the Mediterranean Sea and 

 Indian Ocean are omitted as it is possible that they do not belong in 

 this species. ) 



Encrusting on shells and corallines, often irregular on the surface 

 and the numerous pointed processes give it a very spiny appearance. 

 The marginal zooecia, which are the only ones that can be safely 

 measured, are of moderate size (0.45 to 0.55 mm long by 0.30 to 

 0.40 mm wide), distinct with deep grooves; the front ventricose, with 

 5 to 7 marginal pores between which are low costal ridges. The primary 

 aperture is slightly transverse (average 0.13 mm wide by 0.11 mm long), 

 rounded with the proximal border broadly sinuated ; the vestibular arch 

 definitely beaded; the primary peristome thin, without oral spines. A 



