406 SIGALIONID^]. 



they have been subjected to considerable friction. The most noteworthy distinctions of 

 the French authors are the condition of the second foot, which is exceptionally large, 

 and the commencement of the spinning-glands on the ninth foot instead of the eighth. 

 Further investigation will probably clear up the doubtful points. It has to be stated, 

 however, that considerable variations exist in the common form (P. (Erstedi) in regard to 

 the length and bulk of the second pair of feet. Thus, for instance, these were unusually 

 large in an example procured by the ' Triton ' in 516 fathoms ; arid the median tentacle 

 was also much longer than usual, though it did not reach the tips of the lateral tentacles. 

 The spinning-glands began in this on the eighth foot as in the ordinary examples. 



Family V.— SIGALIONID^E, 1 Kinberg, 18 



-3/ 



Cephalic lobe rounded, often with a nuchal collar posteriorly. No facial tubercle. 

 Median tentacle, when present, generally long, produced from the median part of the 

 cephalic lobe, and with ctenidia at the sides of the base (ceratophore). Lateral 

 tentacles fused with the base of the tentacular cirri, the tips only emerging. Eyes four, 

 occasionally only two, or absent. Palpi long, attenuate and smooth, with buccal ctenidia 

 at the bases. 



Body long and narrow. Pharynx with f yy f§ papillae and teeth. No pregastric 

 caeca. First pair of feet carried in front of the head. Dorsal bristles spinous and 

 tapering. Ventral bristles compound, the terminal region being often long, multi- 

 articulate and bifid. Ctenidia on all the feet. Elytra and cirriform gills alternate in 

 the anterior segments up to the twenty-sixth ; those of the middle and posterior part 

 furnished with both elytra and cirriform gills. 



Granular epidermic area for the nerve-cords deep, the upper arch being covered by 

 the insertions of the vertical and oblique muscles, the latter attached below the former 

 — on each side of the nerve-area — without intermingling to any extent. 



The genus Sigalion was established by Audouinand M. Edwards in 1834, and adopted 

 by Cuvier in the second edition of the ' Kegne animal' 3 for two species, remarkable 

 for their genera] organisation amongst the Aphroditaceans by the simultaneous presence 

 of superior cirri and elytra on all the feet. They did not see eyes in the spirit-preparations, 

 and no branchiae, the fringes of the elytra perhaps taking the place of the latter. They 

 grouped the Sigalionidas under the Aphrodisiens vermiformes along w4th the Acoetes. 



Kinberg's fifth family of the Aphroditea is the Sigalioninze, which he characterises 

 as having a long narrow body, the cephalic lobe rounded, occasionally elongate. No 

 facial tubercle. Tentacle not always present, and generally long, the basal region 



1 Dr. George Johnston observes, (C Perhaps formed from atyaXoeig, curiously or anomalously 

 made ; but Sigalion is a name of Harpocrates, the companion of Esculapius and Hygeia, by whom 

 physicians were obliged to swear that they would observe a religious silence in their profession." 



2 T. iii, p. 207. 



