150 THE ANNELIDA POLYCHAETA. 



in bearing more than two setae of the stout composite kind on the first parapodia, 

 with the distal appendage of these setae fine. It difi'ers clearly, however, in 

 having but four stout setae instead of twelve on the first parapodia, the others 

 being more slender ; in the different form and greater proportionate size of noto- 

 cirri and neurocirri, these exceeding the neuropodium instead of falling short of 

 its tip (as shown by Greeff's figures); and conspicuously in the much stouter 

 ventral paired tentacles. 



Rhynchonerella parva, sp. nov.^ 

 Plate 25, fig. 9, 10. 



The general color is yellow, more dilute in the appendages, which are trans- 

 lucent. 



The type-fragment, consisting of head and twenty-five somites, is 3 mm. 

 long. The body, so far as represented in the type, varies but slightly in diam- 

 eter, being, however, a little narrowest at the anterior end just back of the eyes 

 and widening to near the fifteenth somite, after which there is no change. 



The prostomium projects usually in front of the eyes as a rounded tubercle 

 from which the slenderly conical tentacles arise. The median tentacle is a 

 small, slender process arising above between the eyes at the caudal end of a 

 depression. The eyes are widely separated; the lenses are directed a little for- 

 ward of directly ectad. 



There are five pairs of tentacular cirri arising from the first three somites, 

 one pair on the first (neurocirri) and two pairs on each of the two follo\ving. 

 The first cirri do not reach the outer edge of the eyes, but the dorsal cirri of the 

 next two somites, which are decidedly longer and are subequal, extend clearly 

 beyond the outer limit of the eyes. The ventral cirri of somites II and III are 

 short. 



The uniramous parapodia have the setigerous branch or neuropodium long, 

 a little swollen at base, these cylindrical over most of length and conically 

 narrowed distally, with the tip a slenderly pointed process through which the 

 aciculmn extends, and in addition bearing a single short appendage of the usual 

 type. The notocirri of the posterior region of the fragment have a distinct 

 cirrophore, bearing a lanceolate or narrowly ovate-lanceolate style. Forward 

 the styles decrease in size, but remain proportionately narrow and acutely pointed. 



' parvus, small. 



