638 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 



ern California, 45 fms. One of the latter is almost exactly like the 

 type specimen except that the ovicell encloses three peristomes. The 

 other colony diflfers only in having the 3 or 4 marginal rows of peristomes 

 suddenly much elevated. 



Plagioecia ambigua new species 

 Plate 66, fig. 8 



The zoarium is flat and thin, entirely adnate, encrusting the smooth 

 surface of a shell. The proximal portion is narrowly flabellate, with a 

 very simple ovicell ; beyond this the zoarium becomes broadly flabellate 

 with a similar simple ovicell at one side and a very broad ovicell occupy- 

 ing much of the width of the lobe. The zooecial tubes are elongate, 

 moderately distinct on the surface, slightly cross-striated and perforated 

 with small pores, 0.20 mm in width. The peristomes are only suberect 

 and directed strongly forward, the diameter 0.15 and the round aperture 

 0.13 mm; arranged in quincunx. There is only a single row of incom- 

 plete tubules at the margin. 



The simple proximal ovicell is about 0.40 mm in width by 0.75 mm 

 long; the simple lateral ovicell 0.30 mm wide by 0.70 mm long and the 

 large ovicell is about 1.60 mm broad by 0.80 mm long. The ooeciostome 

 is terminal in the small ovicells, erect at the proximal side of a peristome; 

 in the large ovicell the ooeciostome is similarly situated, but is somewhat 

 subterminal as the ooecial cavity has extended slightly beyond it ; diameter 

 of aperture 0.08 mm. 



Type, U. S. Nat. Mus. no. 11049. 



Type locality. Point Barrow, Alaska, 130 feet, Arctic Research Lab- 

 oratory, G. E. MacGinitie, collector, one colony. 



This is a very unusual specimen, with characters of several genera. 

 There are two simple ovicells like slightly expanded zooecial tubules 

 and with terminal ooeciostomes, much like Oncousoecia diastoporides, 

 except that the ooeciostome is associated with a peristome. There is also 

 a much expanded ovicell, transverse, surrounding several peristomes, 

 with a subterminal ooeciostome and resembling Plagioecia, except for 

 the position of the ooeciostome proximal to a peristome. The latter 

 character is more like that of Tubulipora. The ovicell surrounds a num- 

 ber of peristomes, which would place the species under Diaperoecia. 



With such a combination of characters, one is naturally in doubt as 

 to the generic relationship, but I am accepting as the most important 

 character the fullest development of the ovicell, expanded laterally and 

 with a subterminal, median ooeciostome. 



