96 Bulletin Vanderbilt Marine Museum, Vol. VII 



oblique, augmented by a node on the proximal distal angle. The 

 articulated distal article consists of a blade, roughly triangulate, 

 with the outer margin convex, the inner concave, with an apical 

 and a subapical sharp tooth, also one at the proximal angle. The 

 dorsad setum of the series also bears on the outer side three evenly 

 spaced, articulated small spines. The median row of setae is 

 spaced with the first setum more ventrad than the first one of the 

 first series and with the others intermediate in position between 

 those of the first series, these setae of the second series are similar 

 to those of the first series except that they are shorter and that 

 neither of the outermost two spines has any supplemental articu- 

 ated setae. The posterior or third series of spines are placed in 

 alternation with those of the preceding series ; the spines of this 

 third series are greatly reduced in length but of thick circum- 

 ference distally and obliquely truncated with the distal angles 

 dilated into corrugate rounded nodes, augmenting the short, den- 

 tate distal blades. 



The related notocirral cluster of spines arises adjacent to the 

 foregoing neural cluster and extends very obliquely dorsad. This 

 notocirral cluster consists of six setae in all arranged in fanlike 

 series, of gradually increasing lengths from the ventral to dorsal 

 setae. The setae, 1, 2, 3, 4, and 5, are each composed of a long 

 slender, bowed or curved proximal article, which supports a distal 

 slender, tapered acuminate article, while setum 6, most dorsal of 

 the series and longest, is also stouter and has its outer lateral mar. 

 gin regularly sharply toothed on both articles, there being 8 to 10 

 such teeth, spaced along the side of both joints. 



The branchiae begin on somite XVIII as a simple filament, 

 only one-fourth as long as the related. The second branchia is 

 like the first except that it is longer, being two-fifths as long as the 

 related cirrus. The third branchia is subequal in length to the 

 second one, but has the tip subequally bifid for one-half the length 

 of the branchia. The fourth branchia is equally biramous and is 

 two-thirds as long as the cirrus. The fifth branchia, somite XXII, 

 are two-thirds as long as the cirrus and are two-branched, the 

 distal article being slightly the longer. The sixth branchia is the 

 first tribranchiate, with the proximal or innermost branch being 

 slightly the longest branch, exceeding the cirrus by one-fifth of 

 its length and slenderer than the cirrus, while the second branchial 

 article is a trifle shorter than the third, or distad branch. The 



