236 PROCEEDINGS OF THE ACADEMY OF [April, 



provided with ensheatliing awns which appear to be disposed in sym- 

 metrical pairs. 



Anterior uncini (on III) (fig. 27) have the head little enlarged and 

 somewhat thrown back, the stout, blunt, nearly straight beak some- 

 what elevated, the crest composed of a single large tooth with a cluster 

 of small ones surrounding its base, and the guard rudimentary or ab- 

 sent (fig. 28). In a succeeding tori there is a gradual transition to the 

 typical form which appears at about VI. Such uncini (fig. 29) have 

 a distinct shoulder, well-defined neck and head, and a stout, tapering, 

 hooked beak with an" acute, slightly recurved tip. The crest is well 

 developed and formed of two transverse rows of numerous teeth which 

 are largest at the vertex and become rapidly reduced laterally. The 

 guard is strong and arising well below the beak sweeps boldly beyond 

 and above its tip (fig. 30). 



The type and one other specimen were taken at Station 4,264, off 

 Freshwater Bay, Chatham Strait, 282 to 293 fathoms, on a bottom of 

 green mud. 



Maldanella robusta sp. nov. Plate XI, figs. 31, 32. 



No complete specimen of this species occurs in the collection, but 

 fortunately there are several heads and one posterior end and it is 

 possible to so fit the fragments together as to secure a complete descrip- 

 tion. 



• The worm thus reconstructed is a fine large one, measuring about 195 

 mm. long and 7.5 mm. in diameter at the middle part. Excluding the 

 pygidium there is twenty-one segments, of which the peristomium 

 and first preanal segment are achsetous, II bears setse only, XX setse 

 only on one side, and III to XIX inclusive both setse and uncini. 



The prostomium and peristomium are completely coalesced and 

 exhibit no trace of a dividing furrow or suture. The cephalic plate 

 meets the dorsal profile of the peristomium at an angle of approxi- 

 mately 135° to 150°, so that the ventral length of the head is nearly or 

 quite twice the dorsal. The cephalic plate has a nearly regular ellip- 

 soidal outline, with a length of about twice the width. Its thin margin 

 is elevated all round, highest and most erect behind, thence slightly 

 diminishing in height to a point anterior to the middle where it is 

 folded and sometimes slightly notched. Anterior to this point it 

 again becomes higher and more flaring until it curves into the base of 

 the palpode, from which it is separated by a slight cleft. Except for a 

 faint crenulation, the margin is entire. The median ridge is rather 

 broad and low, but extends through the anterior half or less only of the 



