202 
developed. No otocysts. Five pairs of nephridia open- 
ing on segments 5 to 9. Two or more pairs of esophageal 
pouches, the anterior pair long and slender or club-shaped, 
the others shorter and usually pyriform. No pouches on 
the first diaphragm. 
Recorded from the Mediterranean and from the west 
coast of the United States. 
(ce) A. cristata, Stimpson.” Seventeen chetigerous 
segments. Kleven pairs of gills, the first on the seventh 
segment. Otocysts, closed spherical sacs each containing 
a single large spherical chitinoid otolith. Six pairs of 
nephridia opening on segments 5 to 10. One pair of 
cesophageal pouches, cylindrical or club-shaped. Dia- 
phragmatic pouches (on the first diaphragm) large and 
finger-shaped. 
Found in the Mediterranean, in the West Indies and 
on the eastern shores of North America, south of latitude 
40° N. 
TI. The characters of the ecaudate Arenicolide are 
as follows :——No tail, the parapodia and gills extend to the 
posterior end of the animal. Body generally of an almost 
uniform diameter. Number of gills variable (according 
to age and species), gills branched unilaterally. — Pros- 
tomium simple, conical, non-lobate. | Brain commissural. 
Otocysts closed spherical sacs, otoliths spherical.  Dia- 
phragmatic pouches long and finger-shaped. Cisophageal 
pouches, one pair, flask-shaped. Nephridia with dorsal 
lip bearing somewhat cylindrical digitiform, often 
branched, ciliated vascular processes, ventral lip deeply 
notched in middle, the two halves semi-circular in shape. 
Ova generally oval with thick vitelline membrane (5 to 6). 
(a) A. grubii, Claparéde.*—First gill on segment 12 
** For an account of these species see Gamble, F’. W. and 
Ashworth, J. H.—Q.J.M.S., Vol. 48, pp. 419-569. Pls. 22-29. 
