50 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL.15 



The prostomium has 9 (or only 8) distinct rings. A pair of eyes 

 is clearly visible on the basal ring, or it may be deeply embedded and 

 obscure. A second pair is visible in the distal ring, especially in juvenile 

 or translucent individuals, but less clear in opaque or older specimens. 

 The proboscis has a circlet of 18 terminal papillae and dark paragnaths. 

 The paired macrognaths are ventral in position and have 3 or 4 large 

 teeth each, the largest on the dorsal end. Micrognaths consist of a 

 dosal arc of about 30 pieces, in a double row. There are no ventral 

 micrognaths. 



The proboscidial length, when everted, appears closely annulated 

 because of the regular arrangement of the attached organs (fig. 1). 

 They form successive circlets, each with processes in similar arrange- 

 ment. Starting at the middorsum and progressing to the midventrum 

 (textfig. 2), area I (middorsal) has 2 or 3 processes, II has 6, III has 

 1 or 2, IV has 2, V has one and area VI (midventral) lacks processes. 

 The organs on area II are largest and most conspicuous; those on area 

 I are smallest. The latter are of a single kind, arranged in 2 or 3 ir- 

 regular rows; each has a thick base, a distal pore and a sharp spine 

 (fig. 5) directed orally. Those of area II are of 6 kinds, numbered 1 to 

 6; those on II-l are smallest, those on II-2 are largest. Pieces on II-l 

 are long, slender, falcate, distally bidentate (fig. 7) or rarely tridentate. 

 Those of II-2 are strongly falcate, distally entire (fig. 8). Those of II-3 

 are similar to the preceding but less falcate (fig. 9) ; those of II-4 

 (fig. 10) and II-5 (fig. 11) are long, erect, the tip distinctly bifid; 

 those of 1 1-6 (fig. 12) are also tall and erect, with bifid tip and excavate 

 base. All organs shown for area II are taken from the same series and 

 were drawn to the same scale. 



Area III has one or 2 rows of low, papillar processes with a sharp 

 spine (fig. 6) directed ventrally; they are transversely elongated. Area 

 IV has 2 knobbed processes on each side; they lack a pore. Each con- 

 sists of a short, broad base that terminates distally in 4 short bosses 

 (figs. 2, 3) in symmetrical arrangement; the bosses are directed away 

 from the center of the proboscis. Area V, on each side, has a single, 

 hard, triangular piece with spine (fig. 4) directed obliquely midven- 

 trally and orally ; the pore is subapical, on the outer side ; seen from the 

 front, these processes appear short and triangular. 



Some interesting variations are noteworthy. An individual from 

 intertidal zones in the Puget Sound, Washington, area differs from 

 typical specimens from California as follows: The embedded portions 

 of the proboscidial organs on area II-2 are greatly prolonged such that 



