ARMANDIELLA ROBERTIAN^E. 19 



with a clavate tip. The great ventral longitudinal muscles taper toward the snout and 

 appear to run forward almost to the tip. The mouth opens a short distance behind the 

 anterior end. Nuchal grooves on each side of the snout. 



Body (Plate XCV, fig. 4) characterised by its length and slenderness, and the 

 presence of numerous branchial cirri along the sides, by their conspicuous condition 

 posteriorly, and the presence of four lateral setigerous processes at the base of the caudal 

 appendix. The latter forms a cylinder of considerable length, minutely ribbed trans- 

 versely, and with an uneven margin posteriorly, that is to say, the dorsal edge forms a 

 prominent papilla, the ventral being less prominent, whilst an elevation occurs between 

 them. In the majority the process is gradually narrowed to its base, so that it is really 

 somewhat clavate. The form of the tip, however, varies in the different examples, 

 probably from friction or other injury. The caudal process has a considerable dorsal 

 curvature, and apparently is readily reproduced after removal. The bristles are compara- 

 tively short, simple, curved, and tapering (Plate XCV, fig. 4 a), and seem to present no 

 peculiarity. 



This differs from the Ammotrypane IngebrigtseniL Kiikenthal, 1 from Spitzbergen, to 

 which it is somewhat allied, by the greater number of segments in the latter, which has 

 also dorsal and ventral cirri, an anal region with two longer ventral cirri, and on each 

 side of the group are five small papillaB. Four rings occur between each foot. 



This species was first described and figured by Hansen from the Norwegian Northern 

 Expedition of 1 876. Though somewhat indistinct his figures are recognisable. 



The Ammotrypane Ixvis of Percy Moore 2 (1906) from Alaska appears to be a closely 

 allied form. 



Genus LXXXII. — Armandiella, n.g. 



Head obtusely rounded anteriorly and devoid of eyes, the ventral longitudinal 

 muscles running forward almost to the anterior border. Minute nuchal organs in front 

 of the lateral groove. Body as in the family, but not divided into distinct segments, with 

 lateral cirri, and, at the base, two setigerous tubercles. 



1. Armandiella Robertianj:, Mcintosh, 1908. Plate XCV, fig. 5 — entire animal; Plate 



CII, fig. 15. 



Specific Characters. — Head forming an obtuse, rounded anterior border without 

 eyes, the ventral longitudinal muscles running forward almost to the tip and thus 

 differing from those of Ammotrypane and Ophelia. Minute nuchal organs in front of the 

 lateral groove. Body 14 mm. long, somewhat short and thick, slightly tapered anteriorly, 

 rounded dorsally and grooved ventrally, the powerful ventral longitudinal muscles form- 

 ing a conspicuous ridge on each side almost from end to end. Posteriorly an abrupt dimi- 

 nution occurs at the caudal process, which is directed upward, the free end of the funnel 



1 < Arch. f. Naturges./ 55, p. 147, 1889. 



2 'Proc. Acad. Nat. Sc. Philad./ July, 1906, p. 354, Text-fig. 



