294 THE ANNELIDA POLYCHAETA. 



extend a moderate distance distad. (Plate 45, fig. 3). The compound crochets 

 of the first three parapodia are long and coarse. The distal segment in these is 

 comparatively rather long and distally moderately attenuated bidentate; the 

 superior tooth long, curved forward, narrowly rounded at tip ; the inferior tooth 

 small, acute, and straight; no distinct jutting angle or shoulder proximad of 

 teeth ; the membranous guard rising high above the level of the superior tooth, 

 slenderly attenuated distad and very acutely pointed. The joint very distinct 

 and the distal piece usually bent at a considerable angle with the proximal. 

 (Plate 45, fig. 4). On the fourth to the ninth parapodia, inclusive, the com- 

 pound crochets are replaced by simple, stout setae which distally are narrowed 

 to a fine tip, near the base of which the setae are usually bent. (Plate 45, fig. 6). 



The maxillae are very thin and semitransparent, pigmented only narrowly 

 along some of the edges, where the pigment is black. The carrier of maxillae I 

 is short and rather broad; it is widest anteriorly, narrowed from in front of the 

 middle, the caudal portion being subtriangular, with the caudally directed apex 

 acutely incised; on each half of the corner there is the usual more elevated 

 triangular area, the caudally directed apex of which Ues against that of the 

 opposite one on the median line in front of the caudal incision. The blade 

 narrows evenly and continuously from near the middle distad, the distal half 

 being slender, only slightly curved, continuing evenly the curvature of the 

 proximal portion. Maxilla II of the right side has eleven, mostly somewhat 

 recurved teeth; the inner plate of the left side has eleven teeth, the outer one 

 seven or eight. The right plate of maxillae III is strongly curved and bears a 

 series of ten slenderly acute teeth; the left plate is but slightly curved and bears 

 a series of only six or seven teeth. Each maxilla IV, lying just ectad of the 

 corresponding maxillae III, bears a single acute, dark tooth. (Plate 45, fig. 2). 

 The mandibles are unusually small and are wholly covered. Each masticatory 

 plate diverges from the opposite one in a cephaloectal direction; it is rather 

 slender and distally pointed, with the anterior margin smooth, excepting for a 

 single acute incision nearer the caudal end. The blades are but slightly attached 

 anteriorly; they are very slender. 



Locality. Off Panama: Sta. 3392 (lat. 7° 05' 30" N., long. 79° 40' W.). 

 Depth 1,270 fms. Bottom hard. Bottom temp. 36.4° F. A number of tubes 

 containing the animals in situ were dredged 10 March, 1891. 



This species is characterized by its small size, short median tentacle, bi- 

 dentate, compound, hooded crochets on the anterior parapodia, and especially 

 by the structure and arrangement of the branchiae, these being all simple and 



