l-iO [Assembly 



E.HTNCHOBOLUS DIBRANCHIATUS Ve7'riU. 



Olycera dihrancMata Eulers. Op. cit., p. 670, pi. xxiv, figs. 1, 10-28. 1868. 



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

 Rhynchobohis 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 And and IT. Edw. 

 Annales des Sciences Naturelles, vol. xxis, p. 266. 1833. 



GONIADA SOLITARIA U. Sp. 

 PLATE (IV) VII, FIGS. 41, 42. PLATE (v) VIII, FIGS. 43, 44. 



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

 conical, with minute antennas. 



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 rowa 

 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 scattered 

 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 venti'al. After tlie 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 

 acicnlfe or setse, 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. 



Setge of one kind only ; in two bundles, upper and lower ; upper 

 most numerous ; very long and slender ; the 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°^"" ; width, 1 . S"^"^. 



The only specimen taken was a female filled with eggs ; low 

 water, mud. 



Fam. THELETHUSID^. 



ARENICOLA Lamarck. 



Aeenicola ? CKisTATA Stimpson. 



Stimpson. Proc. Boston Soc. Nat. Hist., vol. v, p. 114. 

 QuATREFAGES. Histoire Naturelle des Annel6s, vol. iii, p. 673. 1865. 



