318 BIOLOGICAL SURVEY OF 



in some cases smaller avicularia are present on the lateral 

 zooecia of the branches. There is great variation in the width 

 of the branches, but none were observed to approach the form 

 quadridentata Loven. The species occurs from southern New 

 England northward to Arctic seas and southward on the Euro- 

 pean coast to the British Islands. It is also found on the 

 Pacific coast as far south as the Strait of Fuca. 



The zoarium is dichotomously divided into broad foliose 

 or ribbon-like strips reaching the height of 1 to 1^ inches. 

 Frequently the branches are narrow and linear (var. fruticosa 

 Packard) and all sorts of intermediate conditions exist. The 

 zooecia are multiserial, in 4 to 12 rows, alternating, oblong, 

 truncate above, and usually narrowed below. The frontal 

 aperture reaches nearly but not quite to the proximal end 

 of the zooecium. There is an erect spine at each distal angle, 

 and a varying number, 1 to 6, of smaller spines bend over 

 the aperture. Avicularia are of two kinds, smaller ones with 

 elongate beaks attached at the middle of the proximal part 

 of the zooecia, and much larger ones, often wanting, attached 

 to the outer margins of the fronds. The ooecia are large, 

 globose, with radiating striae, and are attached across the 

 whole distal end of the zooecium. 



Division VI, Cribkimorpha Harmer, 1926 

 There is much uncertainty among recent students of the 

 Bryozoa concerning the disposition of the old Hincksian Fam- 

 ily Cribrilinidae. Levinsen (1909, p. 156) placed the group 

 in the Suborder Anasca, Group II, Malacostega. Harmer 

 (1926, p. 470) erects the present Division VI of the Anasca to 

 include the ' Cribrimorphs ' of Lang ( 1916 ) . Canu and Bassler 

 (1929, pp. 27, 30, etc.) have separated the group, placing 

 certain genera {Crihrilina, Gephi/rotes) under the Family 

 Alderinidae in the Division Malacostega, while other genera 

 {Puellma, Figularia, CoUetosia, etc.) are located in the Fam- 

 ily Costulae, Suborder Ascophora. 



The simplest and probably most primitive members of the 

 group (e.g., Memhraniporella and Crihrilina) have a complete 



