294 ANNELIDA 



sometimes acting as gills on the anterior or all segments; no proboscis or. 



jaws present: 4 families; wonns burrowing or tubicolous. 



Key to the families of Terehelliformia: 



fli Head without appendages 1. CiEEATULlDAE 



Qz Head with long tentacular filaments. 

 bi Tentacular filaments very long. 



Ci No setae on head 2. Terebellidae 



C2 A bundle of setae on each side of head 3. Ampiiaretidae 



62 Tentacular filaments short 4. Amphictenidae 



Family 1. CiEEATULlDAE. 



Small and medium-sized cylindrical worms which are usually found 

 in burrows or under stones; head distinct but without appendages or 

 proboscis; parapodia rudimentary, but dorsal cirri very long and fila- 

 mentous and acting as gills: sev- 



MUf. 







Fig. 468- 



-Cirratulus grandis (Verrill). 

 1, dorsal cirri. 



C. grandis Verrill (Fig. 468). 



eral genera. 



CiRRATULUS Lamarck. Head 

 conical; cirri veiy long and slen- 

 der, a pair of them being present 

 on almost every segment; a trans- 

 verse row of long branchial fila- 

 ments on one of the anterior seg- 

 ments: many species, 4 'at Woods 

 Hole. 



C. cirratus (0. F. Mliller). 

 Head consists of a prostomium 

 and a peristomial segment; a row 

 of eyes on the prostomium ; length 

 8 cm. ; width 4 mm. : coast of 

 Maine; in tubes under stones; 

 Europe. 

 No eyes present; first 3 segments 



without cirri; color yellowish-green; length 15 cm.; width 6 mm.; length 

 of longest cirri 6 to 10 cm.: Virginia to Cape Cod; in sand and gravel, 

 in shallow water; common. 



Family 2. TEEEBELLIDAE. 



Long and often thick worms living in burrows or tubes; head with 

 a prominent horseshoe-shaped preoral lobe whose anterior margin is 

 reflexed, behind which is a transverse ridge bearing large numbers of 

 long tentacular filaments which act as gills; behind these are usually 

 1 to 3 pairs of branching gills belonging to the anterior segments; para- 

 podia reduced; both capillifonn and hooked setae: numerous species. 



