HESIONE PANAMENA. 189 



ately adjacent to the sulci. The lateral cushion-like region and the parapodia 

 are paler and also with the vague rosy tint excepting the parapodia. The setae 

 are green as in various related species, excepting the distal blades which are 

 nearly colorless. 



The prostomium wider than long; sides strongly convex; convexly elevated 

 above, and with a short median longitudinal sulcus at the caudal end which 

 bifurcates anteriorly. Eyes of the anterior pair decidedly larger and farther 

 apart than those of the posterior pair. Antennae broken off in the type. 



The peristomium dorsally very short and finely longitudinally \vrinkled, 

 while ventrally much longer than usual. The usual eight pairs of tentacular 

 cirri present, of which the dorsal are longer; the second dorsal reaches nearly to 

 the fifth parapodiferous somite. 



Parapodia proximally subcylindrical, distally conical, with the end truncate. 

 The eighth parapodium is 1.5 mm. long, this being about the same length as the 

 setae, or the latter but little shorter. The ventral cirri normally extend a little 

 beyond the distal tips of the setae. The dorsal cirri are long, and apparently 

 entire, one of the posterior region exceeding in length the distance between the 

 tips of the setae of the two parapodia of the same somite, though most of the 

 setae present are shorter than this. The anal cirri are of about the same length. 



The setae are of the prevailing general type. The subapical tooth is small, 

 often rounded, and inserted above the middle of the distance between attach- 

 ment of the covering lamella and the tip of the seta. The lamella extends much 

 distad of the tooth, opposite which it is excavated; it is nearly straight excepting 

 sometimes at its tip, and the space between it and the seta proper is always narrow 

 and slit-like. (Plate 22, fig. 9, 10). 



The proboscis is not extruded in the type. 



Locality. Panama. Shore. 12 March, 1891. One specimen. 



This form in general structure and appearance is near H. splendida 

 Savigny. Augener (Fauna Siidw.-x\ustr. Polych., 1, 1913, 4, p. 187) gives a 

 wide scope to splendida. I believe he includes two or more definitely separable 

 specific forms under that name. Not to mention other differences, an exami- 

 nation of the setae of specimens of H. splendida {sicula Claparede) from the 

 Mediterranean shows constant differences from those of H. panamena, the 

 subapical tooth being decidedly longer and the lamella shorter and not passing 

 beyond the tooth (Plate 22, fig. 11, 12). The figures given by St. Joseph 

 (Ann. sci. nat., 1897, ser. 8, 5, pi. 19, fig. 136) and by Mcintosh (Challenger 

 Annehda, 1885, p. 185, pi. ISA, fig. 10) for this species (under the name of 



