294 



ANNELIDA 



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

 jaws present: 4 families; worms burrowing or tubicolous. 

 Key to the families of Terebelliformia: 



! Head without appendages 1. ClRRATTJLlDAE 



a 2 Head with long tentacular filaments. 

 &! Tentacular filaments very long. 



Cj No setae on head 2. TEBEBELLIDAE 



c 2 A bundle of setae on each side of head 3. AMPHABETIDAE 



6 2 Tentacular filaments short 4. AMPHICTENIDAE 



FAMILY 1. CIKRATULIDAE. 



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- 

 eral genera. 



CIRRATULTJS Lamarck. Head 

 conical; cirri very 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. Miiller). 

 Head consists of a prostomium 

 and a peristomial segment; a row 

 of eyes on the prostomium; length 

 8 cm. ; width 4 mm. : coast of 



Fig. 468 Cirratulus grandis (Verrill). 

 1, dorsal cirri. 



tubes under stones ; 



Maine ; in 



Europe. 



C. grandis Verrill (Fig. 468). 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. TEBEBELLIDAE. 



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 capilliform and hooked setae: numerous species. 



