128 Transactions of the Canadian Institute. [vol. ix 



'roots' a few bands of longitudinal fibres over the surfaces of the glands; 

 a median band of short transverse fibres encircling the body in the median 

 plane; and a short band of similar fibres extending downwards on each 

 side about half the length of the body. That of the left side connects 

 with the atrial siphon and that of the right side with the oral. 



From 17 to 20 tentacles, the largest tripinnate. Aperture of dorsal 

 tubercle horseshoe-shaped, directed forwards and slightly toward the 

 left. Dorsal lamina narrow, its margin smooth; it does not extend be- 

 yond oesophageal aperture. Six folds on each side. Bars on both sides 

 of each fold, as many as 7 on a fold. Stigmata form the usual infundibula 

 and some small accessory infundibula between folds. The stigmata 

 are short and not numerous nor closely placed. 



About 12 shallow gastric folds. Intestinal loop broad anteriorly, 

 straight. Inner margin of anus fused with pharyngeal wall, outer mar- 

 gin smooth or with a single tooth. Gonad fills the intestinal loop and 

 covers its inner side, consisting of a central ovary (its duct following rec- 

 tum) and an upper and lower mass of testicular lobes. The vasa de- 

 jerentia are numerous (9 in one specimen), their free portions short, 

 placed in an irregular row above the middle of the gonad on its inner 

 side. Renal organ below stomach. Heart along right side of renal 

 organ. Glands small, disk-shaped. Ectodermal processes of mantle few 

 or absent. 



Several specimens were collected by the Rev. I. O. Stringer at Hers- 

 chel Island, Arctic Ocean and communicated to me by Prof. Wright. 



Pallas' A. globularis is undoubtedly a Rhizomolgula. The identifi- 

 cation of these specimens with his species rests upon external characters 

 alone. He has given very characteristic figures. Redikorzew's R. 

 gigantea appears to be the same species. 



Family — Styelidcs. 

 Subfamily — PolyzoincE. 



Melandrocarpa dermaiina sp. n. 



Colonies thin, encrusting, dark red or purplish in colour. Indi- 

 viduals irregularly disposed, about 2 mm. distant from each other. 

 They are flattened parallel to the surface of the colony or elongated per- 

 pendicularly to it, depending upon the thickness of the colony. They are 

 from 4 to 5 mm. in length. The colonies are up to 10 cm. in length. 

 The apertures are transverse slits. 



About 24 tentacles. Aperture of dorsal tubercle a transverse slit. 

 Dorsal lamina narrow, its margin smooth. Five bars on each side, the 

 two uppermost approximated. Small transverse vessels cross stigmata. 

 Stigmata narrow, about 50 in a row. 



