SYLLIDJE. 137 



touches on the head and buccal region. The dorsal surface of the segments shows under 

 the microscope transverse striae, somewhat irregularly arranged. 



The proboscis in extrusion (Plate LXV, fig. 10, from Marion and Bobretzky) has a 

 crown of prominent papillae, soft and contractile, and with barbed palpocils, and the 

 adjoining surface has long flexible hair-like papillae. Moreover a symmetrical pair of 

 jaws occurs a short distance within the former, and a slightly tapered tooth or stylet in 

 the middle attached to a dark chitinous socket. The intestine is somewhat sacculated ; 

 the glandular region (urinary, Marion and Bobretzky) commences about the twenty-fifth 

 segment. 



The typical foot (Plate LXIX, fig. 18) is uniramous, having the long cirrus dorsally 

 with a spine in the ceratophore, and a somewhat conical setigerous region with a terminal 

 papilla, supported by two spines, and bearing a fan-like tuft of slender, translucent 

 bristles. These have slightly curved shafts which are a little dilated, striated, and 

 bevelled at the tip (Plate LXXVIII, figs. 8 and 8a), and with long, slender, terminal 

 pieces ; indeed the superior are so long and slender as to resemble those of Nereids, and 

 the minute structure of the tip is indistinguishable. In the shorter forms the tip is 

 hooked and a secondary process appears to be present beneath, whilst the ventral 

 cirrus is subulate, and the edge of the blade is minutely serrated. 



Marion and Bobretzky state that the cirri of the segments adjoining the tip of the 

 tail have no spines in the ceratophores. 



Reproduction, — Marion and Bobretzky found ripe males and females at Marseilles in 

 December and January. 



Habits. — It can swim rapidly after the manner of a Syllis, though the body is much 

 shorter, and the long yellowish cirri make it very conspicuous (Marion and Bobretzky). 



Family IX. — Syllim: (Alitor.). 



The Syllidae are characterized by a thread-like body, definitely segmented, and often 

 with articulated tentacles and cirri, the former and some of the latter being occasionally 

 very long. The head is rounded or quadrangular, has three tentacles— a median and two 

 lateral — and usually four eyes. Palpi, in various degrees of development and separation, 

 are generally present. Buccal segment with two tentacular cirri, rarely with bristles. 

 The alimentary apparatus consists of a mouth opening into a pharyngeal cavity, through 

 which the protrusible proboscis (pharynx, Schlundrohre), which has a chitinous wall, can 

 be exserted. This organ in situ often shows a sinuous outline, has anteriorly a series of 

 soft papillae at its margin, and a little behind a hard prominent tooth, or two maxillae 

 (Grube). It terminates posteriorly in the proventriculus, a region often more or less 

 barrel-shaped and marked by rows of dots from glands. The proventriculus is followed 

 by a short portion— frequently tapering posteriorly— which ends in a dilated region, 

 often with two lateral caeca, 1 and which is marked from the intestine behind by a 



1 Said by Benham (after Meyer ?) to be used for storing water. 



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