48 THE ANNELIDA POLYCHAETA. 



Harmopsides, gen. nov.^ 



Body short, composed of comparatively few somites, colorless and trans- 

 parent. 



Prostomium wider than long, divided into two equal halves by a deep 

 median furrow, each half in outline somewhat diamond-shaped. Tentacles 

 three, inserted marginally. Ceratophores distinct and the styles smooth and 

 subulate. Palpi comparatively long and slender, pointed. 



Parapodia long, with the notopodium represented only by a slight non- 

 setigerous tubercle into which the tip of an aciculum extends. At the end of the 

 neuropodium a digitiform presetal process into which the aciculum penetrates. 

 Notocirri long. Neurocirri attached well distad of the middle of the parapodium, 

 all small excepting the first which is attached near the base of the parapodium 

 and in length is comparable to a tentacular cirrus. 



Setae of two forms, both a modification of the same fundamental type, 

 the first consisting of stouter ventrals with short heads and the second of much 

 more numerous and greatly elongate finer ones of the dorsal portion of fascicle 

 in which the heads are slenderly elongate. Apices of all setae bifid or with a 

 subapical tooth. 



Elytra not known. Eighteen pairs of elytrophores in the type-species, 

 these occurring on somites II, IV, V, VII, IX, and then on alternate ones to the 

 XXIII and thereafter on XXVI, XXIX, XXXII, XXXIV, XXXVII, and XL. 



Armature of the proboscis as usual in the family. 



Genotype. — H. natans, sp. nov. 



This genus is near Nectochaeta Marenzeller, erected for grimaldi Marenzeller, 

 taken in the Atlantic. It is regarded as distinct especially because of the 

 presence of the prominent subtentacular process, the absence of all notopodial 

 setae, and the larger number of somites, the elytra numbering eighteen pairs 

 as against only eleven in Nectochaeta. 



Harmopsides natans, sp. nov. 



Plate 6, fig. 1-5. 



The body of the type as preserved having a very dilute yellow tinge but 

 probably colorless in life, as are the paratypes at present, transparent. 



' o.pixb%, a peg, and &\p, face, in reference to the subtentacular process. 



