Zool.— Vol. I.] JOHNSON— PACIFIC COAST ANNELIDS. 185 



four, black, the two on each side closely approximated. No dorsal cirri; 

 anal cirri similar in shape and length to the cephalic cirri. 



Elytra, 17-19 pairs, borne on somites 2, 4, 5, 7 . . . .33. Elytra varying from 

 trigonal to uncinate, the point of the "claw" toward the median line (fig. 

 56) ; they show distinct concentric growth-lines, and have a deep fringe of 

 knobbed filaments on their posterior and external borders (figs. 56 and 59); 

 the whole exposed upper surface of elytron with minute adherent sand grains. 

 A varying number of elytra, beginning with the second pair, have a central 

 dark spot. 



Peristomial parapodia forwardly directed, with only a single pair of 

 long, curved aciculae and minute, simple, capillary setae like those of all 

 the dorsal rami (figs. 58, dyi). Ventral rami with a fascicle of much stouter, 

 longer setae, with falcate appendages (fig. 63a, 6, c). Ventral cirri short, 

 papillated, knobbed at tip, more or less coiled (fig. 58). 



Jaws (fig. 57) double, strongly hooked at apex, horizontal in position, as 

 seen in situ when retracted. 



Somites 35 to 38 in number, all setigerous except the pygidial. 



Measurements. — Length, 7 mm.; width 2 mm. 



This curious little Sigalionid occurs in Monterey Bay, 

 where I have dredged it in twelve fathoms on a stony bot- 

 tom. They are found crawling over the stones and hiding 

 in crevices. The body is closely incased laterally by 

 the elytra, and further protected by the adherent sand 

 particles, which render it rough to the touch. This singu- 

 lar mode of protection has been adopted, as is well known, 

 in the allied genus Psammolyce. How the sand is held so 

 firmly in place, and how the grains are so accurately se- 

 lected as regards size and kind, is not apparent. Probably 

 a secretion is produced by the dorsal surface and elytra, 

 which hardens very firmly and effectively. 



Sthenelais fusca, sp. nov. 

 Plate IX, Figs. 6o, 61, 6ia-b; Plate X, Figs. 64, t>\a-g. 



Form elongated, tapered at posterior end, somites very numerous (138 or 

 more); general color above, rusty brown, mottled with black, pale below. 

 Elytra, over 100 pairs (112 in one specimen), entirely covering the back and 

 the sides as far down as the parapodia. 



Prostomium (fig. 60) rounded, eyes four, anterior pair placed far forward, 

 nearly concealed under antennae (?) as viewed from above. Tentacle short, 

 slightly moniliform towards tip; antennae (?) very short, flattened, and foliate. 



Peristomial somite with a pair of forwardly directed setigerous parapodia, 

 each bearing two cirri, similar in shape to tentacle and the dorsal one about 



