186 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



Lineus diibius, sp. nov. 



Similar to tiie last in form aud habits. Body very slender in exten- 

 sion, and attenuated posteriorly. Head elongated, narrow. Ocelli ivMte, 

 inconspicuous, forming a simple lateral row of about twelve, extending 

 back on each side of the head, beyond the lateral (nasal) fossie. Color 

 light green to dark olive-green. Length of largest observed, SO™"* to 



'jKmm 



Gloucester, Mass., under stones, between tides, 1878. 



liineus pallidus, sp. nov. 



Long and very slender in extension, subterete, attenuated posteriorly. 

 Lateral (nasal) fossae long and deep. Mouth situated far back. Head 

 elongated, usually obtuse and wider than the body, but very changeable. 

 Ocelli absent.. Color usually whitish or pale ocher-yellow, becoming 

 reddish toward the head, and with a rather indistinct paler dorsal line ; 

 anteriorly there are usually two pale dorsal spots, in front of which the 

 head is yellowish. Length, in extension, 100^™ ; breadth, 0.5™™ toO.To™"'. 



Off Cape Ann, Mass., 45 fathoms, mud, 1878. 



Micrura affinis V. {=^Polia affiniH Girard, iu Stimpsou). 



This species is very common from Massachusetts Bay to the Bay of 

 Fundy, iu 10 to 100 fathoms, on hard bottom. It is usually bright clear red 

 or reddish brown above, rarely varying toward dark olive-green ; beneath, 

 pinkish white ; front of head with a white maigin running back in a short 

 median point. Ocelli black, several in a single row on each margin of 

 the head, the front one largest, variable in number. Caudal filament 

 slender, acute, white. Length, often 125™"i to 150«"' ; breadth, 2">'° to 



A mm 



Micrura inornata, sp. nov. 



Body subterete, moderately elongated, thickest anteriorly, gradually 

 tapered to the somewhat Hattened tail; caudal filament white, very 

 slender and acute, sometimes as long as the diameter of the body, but 

 usually less. Head obtuse, often as wide as the body or wider. Lateral 

 foss« deep, extending to opposite the mouth, the latter not being very 

 far back. No ocelli. Color bright cherry-red, varying to dark red, the 

 middle of the head brightest ; tail pale. Length of largest specimens 

 observed, about 75'"'" ; breadth, O.IO"""' to 0.12""". 



Massachusetts Bay and Gulf of Maine, 45 to 110 fathoms, mud. Re- 

 sembles the young of Cerehratulus luridns V., which occur with it. 



Micrura albida, sj». nov. 



Body thickest and nearly round anteriorly, tapered and somewhat flat- 

 tened posteriorly, with a small, slender, caudal filament. Head obtuse, 

 narrower than the body, l^o ocelli. Lateral fossae short, not conspicu- 

 ous. Color whitish or i^ale yellowish, often becoming light led toward 

 the head ; posteriorly often with grayish or clay-colored internal mottlings 

 along the sides. Very sluggish in its motions. Two si^ecimens from 



