284 THE ANNELIDA POLYCHAETA. 



long. 85° 30' W.). Depth 2,370 fms. Bottom temp. 35.3° F. Several tubes 

 with specimens in situ were dredged 14 November, 1904. 



This species is clearly a very close ally of 0. ehlersi and 0. armandi of Mc- 

 intosh which were secured by the Challenger expedition off the Chilean coast 

 at a depth of 2,225 fms. and midway between Kerguelen and Melbourne (53° 

 55' S. and 108° 35' E.) at a depth of 1,950 fms. From ehlersi it differs in general 

 appearance, apparently, in being a decidedly shorter and stouter form with the 

 somites longer. It differs uniformly in having the branchiae begin on the 

 sixteenth parapodia instead of on the seventeenth, and in the greater length 

 of these, many of which in the present species pass beyond the middorsal line, 

 with the cirri relatively very small. Mcintosh's figure shows the peristomium 

 as shorter than somite II; in the present species the reverse is clearly the case. 

 His figures show the carrier-plate of maxilla I to be proportionately broader 

 and shorter and the blade to be less strongly narrowed distad of the middle. 

 The anterior articulate crochets differ in details. The blade of the pectinate 

 setae is relatively shorter, much broader, and less symmetrical. 



From 0. armandi the species differs in having the branchiae more strongly 

 developed, trifilamentous branchiae occurring prevailingly from the nineteenth 

 to the thirty fifth parapodia, whereas in armandi on the twentieth and thirtieth 

 parapodia the branchiae are only bifilamentous and at the fortieth part have 

 become reduced to single filaments. In armandi the first branchiae are 

 bifilamentous, but in present species are uniformly simple. The carrier-plate 

 of maxilla I is relatively very much shorter, that of armandi being but little 

 shorter than the blades. The species differs from both of these species of 

 Mcintosh in having the anterior edge of the mandibles smooth excepting for 

 a single acute incision. The carrier-plate of maxilla I is much shorter and the 

 blade more abruptly narrowed distad. The setae differ in details, the pectinate 

 setae, e.g., having the distal expansion relatively much shorter and broader. 



Onuphis socia, sp. nov.^ 

 Plate 47, fig. 1-11; Plate 48, fig. 1-4. 



The general color is dilute brown of a pronounced green tinge; a paler 

 middorsal and midventral longitudinal line, which may be discontinuous and 

 not evident anteriorly, is more or less developed. 



The type, Station 4072, the maximum specimen, has a length of 86 mm. 



' socius, associated. 



