422 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
As, however, the whole question of the structure and function of 
the oesophageal pouches of Arenicola is still unsolved, this problem 
must be deferred for the present. 
The discovery of this Mediterranean form upon the Pacific coast 
of North America, and at no intermediate point, is certainly one of 
the most remarkable cases of discontinuous geographical distribution 
ever recorded. 
With exception of a single specimen collected by Miss Robertson, 
I am indebted to Dr. C. M. Child of the University of Chicago for 
all the Puget Sound Arenicolae I have. The specimens were col¬ 
lected by the Columbia University Expedition— exact locality not 
stated. 
While, as von Marenzeller has suggested, it is probable that 
Murdoch’s (’84) Arenicola glacialis from arctic Alaska is none 
other than the circumboreal and widely-ranging A. marina, it is not 
at all certain that the latter species occurs so far south as Puget 
Sound, although it has been reported from Vancouver Island by 
von Marenzeller (’87). 
ClRRATULIDAE. 
39. Cirratulus cingulatus sp. nov. PI. 14, figs. 145-148. 
Form stout, size moderate, tapered at both extremities, decidedly 
flattened on ventral asjmct; dorsum rounded; seven anterior 
somites without setae or cirri; two clusters of 17—18 tentacular fila¬ 
ments (Fig. 145, t. f) each, on dorsal aspect of 8th (the first setig- 
erous) somite; when removed, an oval transverse scar is left; a 
series of similar cirri along each side, in the anterior and middle 
portions of body inserted low (Fig. 146), gradually rising to a higher 
level in the posterior region. 
Somites very short, three-ringed above the dorsal setae, the 
middle ring raised welt-like above the level (Fig. 146). 
Prostomium (Fig. 145) acute, concave on ventral side towards 
mouth, which usually exhibits a partially everted pharynx; eve- 
spots five or six, either in a group or transverse row. 
Parapodia slightly developed (Figs. 145, 146), both dorsal and 
ventral rami with slender, serrated setae (Fig. 147) ; these alone 
are present for 30 setigerous somites back of the head ; the uncini 
appear in the ventral rami (Fig. 148) at this point, and in the 
dorsal rami a few somites caudad ; they continue to end of series. 
