NO. 1 OSBURN : EASTERN PACIFIC BRYOZOA — CHEILOSTOMATA 165 



Genus DENDROBEANIA Levinsen, 1909 



Genotype, Flustra murrayana Johnston, 1847. 



This genus was separated from the old genus Bugula by Levinsen 

 because of the presence of a distinct operculum and the nature of the 

 distal wall which consists of a more horizontal part with a large multipor- 

 ous rosette plate. In addition are the following characters: the proximal 

 end of the zooecium is tubular and nearly transverse (i. e. the proximal 

 end of the zooecium as seen on the dorsal side is not prolonged on either 

 side to form a two-pronged fork, as it does in Bugula) ; there is a more 

 heavily calcified area on the dorsal and lateral walls distally, and in this 

 area are the large single terminal and one or two lateral multiporous 

 rosette plates. 



The species of Dendrobeania are usually multiserial and frond-like, 



erect or more or less recumbent, but occasionally may be biserial. Usually 



there are two sizes of the stalked avicularia, those on the outer zooecia 



being much the larger ; occasionally, however, avicularia may be lacking. 



Key to Species of Dendrobeania 



1. Avicularia present 2 



Avicularia absent 4 



2. Spines well developed, the distal pair erect, lateral ones curv- 



ing over the opesia murrayana 



Spines weak, lateral spines often wanting 3 



3. Occasional small lateral spines ; avicularium, especially the beak, 



elongated curvirostrata 



Only weak spines at distal corners; avicularia stout and bulb- 

 ous ; zoarial fronds very broad multiseriata 



4. A pair of very heavy spines at the distal corners pointing for- 



ward and outward, behind these 4 to 6 strong lateral spines 



on each side bending across the opesia longispinosa 



Spines fewer, shorter and weaker 5 



5. Zooecia loosely connected, sometimes with small fenestrae be- 



tween them ; zoarium semi-erect or recumbent, with irregu- 

 lar branches of greatly varying width laxa 



Zooecia closely connected ; spines sometimes vestigial ; zoarium 



recumbent with broad rounded lobes lichenoides 



s. Dendrobeania murrayana (Johnston), 1847 

 Plate 25, fig. 1 

 Bugula murrayana, Hincks, 1884:6. 

 Bugula murrayana, Robertson, 1900:320; 1905:266. 

 Bugula murrayana, O'Donoghue, 1923:20; 1925 :99; 1926:44. 



The zooecia are elongate, the opesia occupying most of the frontal 

 area; an erect spine at the distal outer angle and a varying number of 

 smaller ones on the inner and outer margins curving more or less over 



