764 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 



Genus BARENTSIA Hincks, 1880 



Pedicellinopsis Hincks, 1884. 

 Ascopodaria Busk, 1886. 

 Gonopodaria Ehlers, 1900. 

 Arthropodaria Ehlers, 1900. 



This genus is distinguished by the presence of a large, barrel-shaped, 

 muscular swelling at the base of the pedicel (a character which it also 

 shares with Coriella Kluge) and by the adnate stolons which never fuse 

 to form erect branches (as they do in Coriella). The pedicel is narrow 

 above the muscular base and is usually well chitinized and stiff; joints 

 occasionally appear in most of the species and in some of them are 

 characteristic. In most of the species the pedicel appears to be more or 

 less perforated, but the outer chitinous layer is complete and there are 

 no pores ■; the cavities are limited to the internal layer. The calyx is more 

 or less ovoid or vase-shaped, the lophophore terminal and transverse, and 

 at its base the calyx is separated from the chitinized pedicel by a short 

 flexible portion. The muscular base permits swinging back and forth, 

 and the short flexible base of the calyx also permits the head to move 

 freely on the pedicel. In at least one species, B. laxa Kirkpatrick, the 

 pedicel is only slightly chitinized, provided with longitudinal muscles, 

 and can be bent or looped in any direction. Genotype, B. bulbosa Hincks, 

 1880a :285. 



The differences in the jointing and branching of the pedicel caused 

 the erection of several other generic names, but there is so much variation 

 in this character that it is often not even of specific value. Some species 

 {e.g. discreta Busk) very rarely are jointed, some others {ramosa Robert- 

 son) are very regularly jointed and branched; sometimes the joints are 

 enlarged and muscular, or the muscular enlargement may be wanting. 

 These characters have some value for the determination of species but 

 are scarcely valid for the separation of genera. 



Key to Species of Barentsia 



1. Upper half of the basal internode and the whole of the short 



second internode thin-walled and flexible ; base of the lower 



internode well chitinized subrigida 



Stalks with chitinized walls, not flexible 2 



2. Stalks never branched, usually without joints 3 



Stalks more or less jointed and branched, the nodes often 



much enlarged 5 



