780 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 



g ^' Escharoides jacksoni (Waters), 1900. 



f' ^^ Plate 81, fig. 8 



Smittia Jacksonii Waters, 1900:87. 

 Escharoides jacksoni, Nordgaard, 1918:55. 

 Peristomella (Escharoides) jacksoni, Osburn, 1923:10. 



Zoarium encrusting, the ectocyst reddish-brown. The zooecia are large, 

 0.65 to 1.0 mm long by 0.50 to 0.65 mm wide; the frontal a pleurocyst 

 with numerous large areolar pores between which narrow costal ridges 

 extend upon the front, usually leaving a smoother central area but some- 

 times extending to the tip of the high lip of the peristome. The zooecia 

 are considerably inflated and elevated toward the distal end, ovate in 

 form and arranged in quincunx. The most striking feature is the form 

 of the peristome which is unusually high above the proximal border of 

 the aperture, where it is more or less pointed, and extends sharply down- 

 ward on each side to the first spine, resembhng an inverted scoop; it 

 lacks the median denticle near the tip which is found in some others of 

 the genus. There are 4 stout oral spines, the proximal pair usually remain- 

 ing at the corners of the ovicell. The aperture is large, 0.20 to 0.26 mm in 

 either direction, rounded proximally, and broader at the distal end, 

 where it is broadly arcuate or sometimes nearly transverse. There are 

 no condyles and no lyrula. The avicularia are large and conspicuous, 

 situated characteristically at one or both sides of the peristome and 

 directed laterally, but often located more proximally on the front and 

 directed more or less backward, often wanting; the rostrum is elevated, 

 the mandible hooked at its tip and measuring 0.25 to 0.30 mm in length 

 and 0.15 to 0.20 mm wide at the base. 



The ovicells are correspondingly large, averaging 0.40 mm in width 

 and length, hyperstomial, hemispherical and conspicuous, perforated but 

 with a small central imperforate area on the top. 



It is an arctic species, described from Franz Josef Land and recorded 

 from Greenland and the western part of the American Archipelago. 

 The following record extends its distribution much farther to the west 

 and it is evidently a circumpolar species. 



Point Barrow, Alaska, Arctic Research Laboratory, 453 feet, G. E. 

 MacGinitie, collector. 



Porella minuta (Norman), 1868 

 Plate 81, fig. 9 



Lepralia minuta Norman, 1868:308. 

 Porella ininuta, Hincks, 1880:326. 

 Porella alba Nordgaard, 1906:25. 



n 7j- „.: j_ XT_„j J inio.'7i 



