776 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 



Zoarium encrusting on stones and shells, the ectocyst sometimes with 

 brown pigment. The zooecia are arranged more or less regularly in 

 quincunx, length 0.60 to 0.80 mm, width 0.35 to 0.60 mm, varying 

 much in form, separated by slightly elevated thin margins which are 

 decorated with coarse granules. The most striking feature is the thick, 

 finely granulated cryptocyst which covers the proximal half or more of 

 the frontal area and extends narrowly around the sides of the trifoliate 

 opesia. Spines are entirely absent from our specimens, though small ones 

 are said to occur occasionally. Avicularia are rare, somewhat elevated, 

 usually located near the proximal end and directed either forward or 

 backward, the mandible short-pointed. 



The ovicell is hyperstomial, prominent ; in final calcification there is a 

 strong arcuate transverse rib which often rises to a central point, and 

 proximal to this is a semilunar smooth area ; width 0.25 to 0.30 mm. 



It is a northern and arctic species, evidently circumpolar; in Atlantic 

 waters it extends southward to the British Isles and to the Maine coast 

 of North America, but it has not been recorded from the Pacific coast 

 before. 



Point Barrow, Alaska, Arctic Research Laboratory, 262 to 328 feet, 

 G. E. MacGinitie, collector. 



Bugula flabellata acuminata new variety. 

 Plate 81, figs. 3 and 4 



The zoarium is erect with broad flabellate branches, the secondary 

 branches biserial but sometimes becoming quadriserial near the tips. The 

 mode of branching is like that of flabellata and the origin of the zooecia 

 is also similar, with long prongs extending distally down the dorsal sides 

 of the preceding zooecium. Height of colony about 20 mm. 



The zooecia are long and slender, length 0.55 to 0.75 mm, width at 

 base 0.13 mm and widening gradually to 0.15 mm near the tip; the 

 membranous area extends nearly but not quite to the proximal end, 

 narrowing downward ; there are no jointed spines, but the distal corners 

 are extended into short, stout processes, sometimes wanting on the inner 

 corner. The avicularia, present on nearly all of the zooecia, are attached 

 by a short stalk more or less above the middle of the zooecium but not 

 near the extremity ; moderately large and somewhat compressed, length 

 0.20 to 0.30 mm, width 0.08 to 0.10 mm, height 0.13 to 0.15 mm; the 

 beak sharply decurved at the tip with a narrow rounded point. The 

 mandible, 0.15 to 0.20 mm long, is unique in my experience as it sud- 

 denly becomes constricted near its distal end into a long acuminate 

 recurved process sharply differentiated from the basal part. 



