PHYLLODOCLCLE. 41 



Synonyms. 



1875. Nephthys pansa, Ehlers. Zeitsch. f. w. ZooL, xxv, p. 40, Taf. hi, f. 1 and 2. 

 1881. „ „ Horst. Mederl. Arch. Zool. Suppl., Bd. 1, p. 7. 



Habitat— Dredged in 426—458 fathoms on July 30th, 1869, 51° 1' N., 11° 21' W., 

 in the ' Porcupine ' Expedition of that year. 



Fig. 40. — Foot of Nephthys pansa, after Ehlers. Enlarged. 



As only a single specimen of this form (about 66 mm. in length) was procured in the 

 4 Porcupine ' Expedition of 1869, the minute details of its structure are in need of further 

 examination (Figs. 39 and 40). It seems to approach Nephthys incisa and N. nuclipes, as 

 Ehlers states, but whether it is a variety of the former or a distinct species appears to be 

 an open question. The form of the branchia is certainly peculiar. 



FAMILY VIL— Phtllodooidjb. 



Head bluntly conical, trapezoidal, cordiform, or sub-oval; sub-tentacles two, as 

 short subulate organs (Grube) ; tentacles two or three, the unpaired posterior. Eyes 

 two, posterior, generally small, rarely four. Large eyes exceptional, and in some probably 

 only in the epitokous forms. Body long and vermiform, rounded or depressed, segments 

 numerous ; caudal cirri two, short. Buccal segment with one to four pairs of tentacular 

 cirri. Proboscis long, bipartite, with short papillse ; no jaws. Blood colourless. Feet 

 as a rule simple, with one spine and a fascicle of compound bristles ; capillary bristles in 

 certain epitokous forms. Dorsal and ventral cirri foliaceous. 



In the Phylloclocicla3 the body-wall as a rule (Fig. 41) has much less massive muscles 

 than in the ISTephthy elicit. The cuticle lies on a thick cellular hypoderm within which 

 are the basement-membrane and the circular muscular layer. The nerve-cords are in the 

 mid-ventral line and more or less in approximation. The oblique muscles generally pass 

 down on each side of the nerve-cords to be inserted into the basement-membrane, though 

 these muscles may decussate quite beneath them and thus press the nerve-cords inward. 

 No neural canals occur in this family in Britain. The dorsal longitudinal muscles are 



63 



