234 TEREBELLID^. 



Fam. XV. TEREBELLIDJE. 



Amphitrites, De Montfort, ConchioL Syst. ii. 15. 

 Amphitrites ter^belliennes, Savign. Syst. Annel. 69. 

 TEREBELLiDiE, Johnstou in Ann. Sf Mag. Nat. Hist. xvi. 447. 

 TEREBELLiE, WHUams in Rep. Brit. Assoc. 1851, 193-4, 206 & 266 

 Terebellacea, Grube, Fam. Annel. 17. 



Char. Body vermiform, cylindrical, generally inflated or thicker 

 in front, the posterior portion of less diameter, and sometimes di- 

 stinctly defined as a bristle-less appendage : head not defined nor 

 separate from the buccal segment, furnished with numerous filiform 

 extensile tentacula placed on the crown, or on a lobe above the 

 mouth, or on each side near the mouth beneath the lobe : post-occi- 

 pital segment, in some genera, armed on the dorsal margin with a 

 transverse row of stiff golden bristles ; and also with small lobes or 

 cirri : mouth terminal, transverse, unarmed : setigerous tubercles of 

 the segments almost always biserial, uniform in relative position, the 

 dorsal with setaceous bristles, the ventral with a double or single 

 series of hooks or uncini : on the posterior portion of the body the 

 dorsal setse, or both the dorsal and ventral, are frequently wanting : 

 branchiae much branched or pectinated, rarely filiform, placed late- 

 rally, rarely in the medio-dorsal line, confined to the two or three 

 anterior segments. — Tubicolous, the tube arenaceous, open at both 

 ends. 



A. Front not armed with a row of stiff bristles. 



38. TEREBELLA. 



Terebella, Montagu, Test. Brit. xxx. ; and in Linn. Trans, xii. 340. 

 Cuv. Regn. Anim. iii. 193. Lam. Anim. s. Vert. v. 353. Savign. 

 Syst. Annel. 69 & 83. 



Char. Body elongate, ventricose anteriorly, strengthened under- 

 neath with a broad fleshy segmented band extended from the second 

 to the fourteenth or an ulterior segment, where it terminates in a 

 point ; the part of the body posterior to the eighteenth or twentieth 

 segment prolonged in a cylindrical tail composed of numerous seg- 

 ments, of which the three or four last form a short tube, folded 

 underneath, and terminated by a plaited and circular vent. Mouth 

 with two transverse lips, the upper prominent, vaulted, surmounted 

 with numerous tentacula; the inferior narrow, plaited: tentacula 

 very long, filiform, very extensile, furrowed below, and roughish 

 with mucous granules : three anterior segments without appendages, 

 or with anomalous ones ; the first has sometimes two inferior semi- 

 circular leaflets contiguous at their base, separate at their tops, and 



