RESEARCHES IN HELMINTHOLOGY AND PARASITOLOGY. 1 77 



commenced development. Fig. 12 represents an individual further 

 developed, from the same tube as the former. It measured half a 

 millimeter long. The body is distinctly divided into nine segments, 

 of which eight bear a pair of setae on each side. The tentacular 

 lobes exhibit each the rudiments of four tentacles. Eyes also have 

 made their appearance. Fig. 13 represents a 3'oung worm from an- 

 other tube, the only one accompanying its parent. It measured 0.72 

 mm. long. The body is divided into the same number of segments as 

 in the former. The tentacular lobes have developed each four tenta- 

 cles, with the rudiment of a fifth. Podal hooks could be detected 

 in none of the segments except the last, in which there were three 

 comb-hooks on each side. Another young individual, observed from 

 another tube, about the same size as the preceding, had five tenta- 

 cles on each side, but was otherwise exactly similar. Another 

 individual, three-fourths of a millimeter long, with five tentacles 

 on each side, had one more setigerous .segment than in the others. 



The species of Fabricia to which I referred in the beginning of 

 the present communication, and which I examined with particular 

 interest on account of the near relationship of Manayiiukia to it, is 

 the same as that described by Prof. Verrill as being common from 

 New Haven to Vineyard Sound and at Casco Bay. (See Report on 

 the Sea Fisheries of New England, Washington, 1873, p. 619.) I 

 first noticed the worm at Newport, Rhode Island, in 1858, and 

 found it abundantly at Bass Rocks, Gloucester, Mass., in 1882. It 

 occurred on rocks between tides, under a luxuriant growth of Fucus 

 vesku/osiis, with its tubes projecting from among the mud and sand, 

 firmly fixed together with multitudes of little mus.sels about the 

 roots of the seaweed. 



The worm is three or four millimeters long and of a yellowish or 

 yellowish brown hue, with more or less reddish. The body is com- 

 pressed cylindrical and slightly tapering behind, and is divided into 

 twelve segments, including the head. This is prolonged dorsally 

 in a half elliptical process or upper lip. The vertex supports on 

 each side a tri furcate lophophore, each fork of which is provided 

 with a double row of narrow cylindrical tentacles invested with cilia. 



The segments succeeding the head are furnished with lateral 

 fascicles of podal setae, and, except the first one, are provided with 

 fascicles of podal hooks, all of which have the same general arrange- 

 ment and form as those described in Manayunkia. The fascicles of 

 podal setse, from the first to the eighth segments, usually contain 

 six or seven setae ; those of the ninth and tenth segments, three or 



