CHAETOPTERUS. 119 



with De Quatrefage's sedentary forms), and placed them between the Maldanidse and 

 ChloraemidaB ; while Leuckarfc thought they approached the Ariciidse. The body presents 

 three distinct regions, viz. anterior, middle, and posterior ; the middle region he associated 

 with respiration. De Quatrefages had only a single genus, viz. Chaetopterus, for he 

 placed Spiochaetopterus under the head of those of uncertain position. Though De 

 Quatrefages could not distinguish blood-vessels on the surface, he considered the regular 

 to-and-f ro movements of segments twelve to fourteen as respiratory, the integuments 

 being very thin. 



Claparede (1870) draws attention to the prevalence of phosphorescence in this 

 family, and specially describes the condition in Chaetopterus variopedatus. In his work on 

 the 'Histology of the Sedentary Annelids' he enters minutely into the structure of 

 Chaetopterus and Telepsavus, as already indicated. 



The ChsetopteridaB constituted the second family of Levinsen's (1883) Syllidiformia 

 Spionina, the first being the Spionida3, and the succeeding the Cirratulidae. In this he 

 more or less adopted Malmgren's arrangement, but the other families associated with 

 them do not conduce to a homogeneous group. He arranges the genera thus : — Spio- 

 chaetopterus ; Chaetopterus. 



Joyeux-Laffuie 1 (1890) and Gravier 2 (1909) both describe reproduction of the anterior 

 region in Chaetopterus variopedatus ; the latter giving excellent figures of his example. 



Haecker (1896) refers to the Chastopterids as having pelagic larvae (Mesotrochous). 



Benham 3 (1896) grouped the Chastopteridee as a family of his sub-order Spioni- 

 formia, following in the main the classification of Levinsen. 



Lillie 4 (1909) experimented with the eggs of this form, and found that the formation 

 of the polar globules was independent of centrifugal force. 



The Chsetopteridae are found both between tide-marks and in deep water. The 

 littoral forms inhabit parchment-like tubes, to which are attached fragments of stones 

 and shells, and they are often hirsute with algaa and Zoophytes. In" Scottish waters, 

 however, especially on the eastern shores, C. variopedatus is a deep-water form, and so 

 with an example procured by the ' Porcupine ' of 1870, off Cape de Gratte, in 81 fathoms. 

 In its spacious tube (occasionally 50 cm. long) in the south it has Polynoe setosissoma, 

 Sav., Gattyana cirrosa, Pallas, and the Polyzoan Hypophorella ch&topteri, Joyeux-Laffuie, 

 as commensals. Only Phyllo chaetopterus, Banzania, and Spio chaetopterus were dredged by 

 the 6 Challenger.' Their affinities, as Sars observed, appear to be with the Spionidse. 



Genus XCIV. — Ch^topteeus, Cuvier, 1830. 



Tricmlia, Eenier. 



Head with the prostomium and peristomium fused, and forming a funnel-like 

 apparatus for the mouth. It gives origin to a pair of grooved tentacles with an eye at 



1 ' Archives Zool. exper./ 2 e ser., t. viii, pi. xv — xx. 



2 ' Ann. Sc. nat./ 9 e ser., t. ix, p. 146, figs. 1 and 2. 



3 Op. cit., p. 323. 



4 ' Biol. Bull. Woods Hole, Mass./ 1909, p. 52, "Polarity and Bilaterality of the Annelid Egg." 



