SIGALION. 123 



5. SIGALION*. 



Sigalion, Aud. ^ M.-Edw. Lift, de la France, ii. 103. Cuv. Rhgn. 

 Anim. iii. 207. Johnston in Ann. Nat. Hist. ii. 428 & 438. 



Char, Body linear-elongate, the scales and superior cirri coexistent 

 on the same feet, the former placed over every alternate foot until 

 the 27th segment, whence they follow uninterruptedly to the anal 

 extremity : proboscis with corneous jaws ; antennae three ; palpi 

 two, large ; eyes four, concealed : feet biramous : anal segment with 

 two styles. 



This genus is distinguished from every known Annelid by the co- 

 existence of superior cirri and scales on the same foot. The body 

 is elongate, depressed, almost linear, and formed of numerous seg- 

 ments. The disposition of the cephalic extremity is singular ; for 

 the head, in place of being exactly terminal, is overtopped by the 

 first pair of feet, which are lodged underneath it, and more or less 

 approximated to the mesial line. Tn our native species there are 

 three cranial tentacula, but in a foreign species the odd one is want- 

 ing, and the lateral are always small, and lie upon the peduncles of 

 the first feet. The palpi, on the contrary, are long, and are placed 

 outside and under these feet, of which the two terminal cirri are 

 pointed forwards, and may be mistaken for true antennae. There 

 appear to be no eyes. The mouth is inferior, and is the outlet to 

 a proboscis similar to that of Polyno'ey but armed with less powerful 

 jaws. At the superior base of every foot there is a rounded protu- 

 berance which gives origin to a cirrus, and which also carries a scale 

 on such feet as have this appendage, — a fact inconsistent with the 

 theory which maintains that the scales are mere modifications of the 

 cirri. On the anterior part of the body the scales appear and disap- 

 pear on every other segment, but subsequent to the twenty-sixth 

 pair of feet there is one to each segment, and two or more to the 

 last two segments, so that their number is always considerable. The 

 feet are distinctly divided into two branches ; the superior branch 

 terminated with a single brush of bristles, the inferior sometimes 

 with one and sometimes with two, but the bristles are shorter. The 

 inferior cirrus is very obvious, and is inserted far from the extremity 

 of the foot. The appendages of the anal ring form two tentacular 

 styles. As to the branchiae, there is no trace of them at the base of 

 the feet, and when Audouin and Edwards inform us that they seem 

 to be replaced by the fringes which garnish the external margin of 

 the elytra, they surely forget that these fringes are not more deve- 

 loped than they are in Polynoe, and their structure is very unlike 

 that of a respiratory organ. 



* Perhaps formed from aiyaXoeis — curiously or anomalously made — but Siga^ 

 lion is a name of Harpocrates, the companion of ^sculapius and Hygeia, by whom 

 physicians were obUged to swear that they would observe a religious silence in 

 their profession. See Sprengel, Hist, de la Medecine, i. 136. 



