Annelida Ch^etopoda of New Jersey. 117 



Rhynchobolus dibranchiatus Verrill. 



Qlycera dibranchiata Ehlers. Op. cit., p. 670, pi. xxiv, figs. 1, 10-28. 1868. 



Grube. Op. cit., p. 64. 1869. 

 Rhynchobolus dibranchiatus Verrill. Op. cit., p. 596, pi. x, figs. 43, 44. 1874. 

 " " Webster. Op. cit., p. 245. 1879. 



Common ; low water to fifteen feet. 



GONIADA Aud. and M. Edw. 

 Annales des Sciences Naturelles, vol. xxix, p. 266. 1883. 

 GrONIADA SOLITARIA U. Sp. 



PLATE IV, FIGS. 41, 42. PLATE V, FIGS. 43, 44. 



Head as long as the first seven segments taken together, acutely conical, 

 with minute antennae. 



Eyes small, black, circular, lateral, posterior. 



Proboscis not seen in complete extension, covered with numerous longitudinal 

 series of stout hooks ; on the dorsal surface three rows of hooks on either side 

 of a naked median space ; on the ventral surface four rows, two on either side of 

 the median line ; one lateral series ; ventral and lateral hooks smaller than the 

 dorsal ; at the base, on the ventral surface, numerous, quite small hooks scat- 

 tered about irregularly. 



The first twenty-five segments are uniramous; the ramus has two lips 

 (fig. 41), anterior long and narrow; posterior short and broad; dorsal and 

 ventral cirri widely divergent, bluntly conical, dorsal a little shorter than ven- 

 tral. After the twenty-fifth foot a dorsal ramus appears (fig. 42), composed 

 at first of a broad, thick, squarish plate, with a slight emargination near its upper 

 margin, indicating its future division into lips; it contains from three to six 

 straight aciculae or setae, usually concealed, sometimes projecting slightly ; the 

 dorsal cirrus becomes smaller ; the other parts of the foot do not change much ; 

 further back the dorsal ramus is divided into two bluntly rounded lobes (fig. 43). 



Anal cirri long, filiform. 



Setae of one kind only ; in two bundles, upper and lower ; upper most numer- 

 ous ; very long and slender ; appendix nearly as long as the stem (fig. 44). 



Body slightly convex above, flat below, anterior two-thirds of uniform width, 

 tapering a little along the posterior third. 



Color gray, slightly tinged with green. 



Length, 25 mm ; width, 1.3 mm . 



The only specimen taken was a female filled with eggs ; low water, mud. 



Fam. THELETHUSID^E. 



ARENICOLA Lamarck. 



Arenicola? cristata Stimpson. 



Stimpsost. Pi-oc. Boston Soc. Nat. Hist., vol. v, p. 114. 

 Quatrefages. Histoire Naturelle des Annexes, vol. iii, p. 673. 1865. 



Only the anterior part of a single specimen was found. Probably belongs to 

 Stimpson's species. 



