54 THE ANNELIDA POLYCHAETA. 



the outer setae on the proximal side are much shorter than those in the inner 

 part of the fascicle and on the distal side. Each notopodial is slender and gently 

 curved; the smooth apex is short and acute with no trace of. a subapical tooth; 

 the conspicuous pectinae extend from the tip over nearly the whole length of the 

 exposed portion of the seta, the smooth proximal portion of the shaft being 

 short. (Plate 2, fig. 4-6 ; Plate 3, fig. 1). 



The elytra are all missing in the specimens studied. The elytrophores 

 have the usual arrangement, occurring on somites 2, 4, 5, 7, etc. They are 

 short and proportionately thick and present the usual subelliptic to ear-shaped 

 scars. 



The body is greyish, in part of a dusky tinge; a darker area on each somite 

 at each lateral end on the ventral surface and a dark ring about the proximal end 

 of each neurocirrus. The notopodial setae are orange in appearance. The 

 neuropodials are paler, dilute yellow. 



Locality. Panama: Perico Island. Shore. 26 October, 1904. One 

 specimen. Panama: Taboguilla Island. Shore. 30 October, 1904. One speci- 

 men. 



Harmothoe mexicana, sp. nov. 

 Plate 1, fig. 1-9; Plate 2, fig. 1. 



The body is well pigmented, being in general a rather dark brown with 

 the parapodia a shade lighter. There is typically a paler narrow median longi- 

 tudinal stripe along the venter. The palpi and the other appendages of pro- 

 stomium and peristomium are yellowish to whitish as are also the cirri. Seg- 

 mental papillae whitish. Setae yellowish. 



The body narrows strongly cephalad from the fifth or sixth somite, the 

 anterior end appearing convexly rounded laterally as well as anteriorly. From 

 the fifth or sixth somite, the region of greatest width, the body proper narrows 

 continuously caudad and at the caudal end is very narrow; however, the para- 

 podia, with their setae, increase in length from the anterior end toward the middle, 

 so that the decrease in width of the body proper is offset for a considerable 

 distance. In the region of the greatest width the depth is about the same as the 

 width exclusive of the parapodia; the depth is less cephalad of this level and 

 decreases caudad from it in such manner that the caudal region may appear 

 conspicuously flattened. A specimen 39 mm. long has a maximum width to the 



