420 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
somites from second to twenty-third; (2) smaller serrated setae 
together with (1) in dorsal rami; (3) ventral setae in first three 
setigerous somites in form of a stout, acute spine (Figs. 134, 136); 
(4) very long, filamentous, spiral setae in dorsal rami beginning at 
7th to 11th somites and continuing to 23d somite (Fig. 138); (5) 
uncini (Fig. 137) of the usual form in this family, in all setigerous 
somites back of the 4th. 
Length of much-contracted specimen (impossible to measure 
accurately on account of twists and flexures), 50 mm.; diameter 
through thickest portion, largest specimen, 1.75 mm. 
The only specimens of this odd little species were collected by 
Miss Robertson at Alki Point, Aug. 3, 1898. The species bears 
a close superficial resemblance to Ficomache lumbricalis (Sars) 
Malingren, but has one achaetous somite in front of the pygidium 
instead of two. 
The long, silky, spiral filaments shown in Fig. 138 have not, I 
believe, been hitherto described in any Maldanid. Whether they 
are permanent structures peculiar to this species, or “ nuptial setae” 
(Pubitiitsborsten) which develop only at sexual maturity, is an 
interesting question. Filamentous nuptial setae of a similar form 
have been described by Michaelsen (’92, p. 6) in a Polynoid 
(Driescliia pelayica ). 
Ammocharidae. 
37. Ammochares occidentalis sp. nov. PI. 14, figs. 140-142. 
Form cylindrical, tapering towards posterior end ; 23 (?) somites, 
of which 20 are setigerous. 
P eristomium produced into ten thick, bluntly-ramose “ tentacles ” 
(Fig. 140) which rise to a level, giving anterior end of body a trun¬ 
cated appearance. Capillary setae in fascicles placed high on dor¬ 
sal surface (Fig. 142), very slender, acutely pointed, silvery by re¬ 
flected light, serrated. Uncini very minute, two-hooked (Figs. 141 
a, 5), 16-18 horizontal rows in each band (6th somite), extend¬ 
ing three quarters of the way around the body; begin at 4th somite. 
Second and third somites (Fig. 140) very short, third twice the 
length of the second, both with rudimentary parapodia (?). Somites 
4, 5, 6, 7 the longest of the body ; from the 7th diminishing gradu¬ 
ally to end of series. 
