592 EEPOET OF COMMISSIONER OF FISH AND FISHERIES. 



the body composed of numerous short segments, on which the feet are 

 famished with lameliiform appendages. 



This remarkable annelid bears some resemblance, in the structure of 

 the body and " feet," to Heteronereis, and there is probably another form 

 to which it bears the same relation that Heteronereis bears to Nereis ; but 

 the structure of the head is very unlike that of any known genus, and, 

 indeed, would not allow it to be placed in the family of Nereldce without 

 modifying the family-characters. There are are no large palpi, corre- 

 sponding to those of Nereis, and nothing to represent them, unless two 

 small lobes close to the mouth be considered rudimentary palpi. 



Nectonereis meg-alops Yerrill, sp. nov. Plate XII, figs. 62, 63. (p. 



440.) 



Body slender, consisting of two parts ; the anterior portion, contain- 

 ing fourteen setigerous segments, is broadest in the middle, tapering 

 both ways, and separated from the posterior portion by a distinct con- 

 striction j the posterior portion is much longer and more slender, taper 

 ing gradually to the end, and consists of very numerous short segments, 

 which are furnished with complex lateral appendages, with thin lamellae 

 and compound bladed setce. Head broad oval, somewhat convex, and 

 very smooth above ; the lateral margins a little convex ; the front 

 obtusely rounded. Byes very large, convex ; the anterior ones largest, 

 lateral and partially dorsal, oval ; in contact with the posterior ones, 

 which are somewhat smaller and more dorsal. Two small decurved 

 antennae, with swollen bases, are on the ventral side of the head ; two 

 small, rounded processes in front of the mouth. Tentacular cirri 

 slender, the upper pair much the longest ; the rather short lower pair 

 arising near the mouth ; the two intermediate pairs arise behind and 

 close to the anterior eyes ; all are slightly annulated. The " feet " on the 

 first seven segments have a large dorsal cirrus, increasing in length 

 from the first to the seventh, narrow at base, swollen and gibbous 

 toward the end, with a slender, oblique, terminal portion ; on the seven 

 following segments the dorsal cirri arc smaller, slender, tapering; 

 the ventral cirri are small, with swollen bases on the first five seg- 

 ments, slender and tapering on the rest; the intermediate lobes of the 

 feet are small and rounded, but more elongated on the first five seg- 

 ments. Setae of different forms, many of them with a slender, often 

 curved, acute terminal piece. 



The lateral appendages of the posterior region have, on the upper 

 ramus, a long, slender dorsal cirrus, strongly crenulate-lobed on the 

 lower side; a Bmall, rounded lameliiform process above its base; and a 

 long, lanceolate process arising just belowit, and in length eqnaling 

 the cirrus; an ovate setigerous lobe, bearing a broad fan-shaped fascicle 

 of compound seta), extending about to the end of the dorsal cirrus; 

 and a lower ovate-lanceolate lameliiform proces i, \\ ith the base expanded 

 and extending backward, the tip reaching to about th third of 



