SIGALION. 125 



cartilaginous proboscis about an inch long, armed with two pairs of 

 sharp horny teeth plain on the margin, the aperture encircled with 

 a double series of papillary tentacula, the outer series much longer 

 than the inner, which liowever is the most numerous. Scales imbri- 

 cate, kidney-shaped, convex, roughish, the concealed portion pale, 

 the outer and larger inargin fringed with very delicate hairs and 

 some short anomalous processes ; there are about 140 scales on each 

 side, each affixed to a fleshy tubercle, from the end of which a ten- 

 tacular filament is extended, equal to the feet in number, and placed 

 exactly above them. Feet extremely numerous, obtuse, bifid, the 

 superior branch papillary, with a brush of long vmequal bristles 

 curved upwards, the inferior branch truncate, somewhat sinuate, 

 with two brushes of short bristles, and underneath with a setaceous 

 cirrus equal to the superior. Bristles of superior branch setaceous, 

 unjointed, serrulate on their upper half, with a spine in the centre of 

 the brush ; the bristles of the inferior branch are most of them stout, 

 enlarged near the top, and terminated with a sort of claw toothed on 

 the inner side ; some of these are marked with a few circular strise 

 below the joint, and there is a spine in their centre ; there are other 

 more slender bristles which are two-jointed, the apical joint longish, 

 acute, and smooth. Ventral surface pale, perlaceous, marked down 

 the middle with a red vessel. Tail terminated with two short fila- 

 ments. When killed in fresh water the scales readily drop off, and 

 the relaxed body of a large specimen will then measure ten or twelve 

 inches. Young individuals are generally of a light grey colour. 

 When placed in a basin of sea- water it appears sluggish, but it bur- 

 rows in loose sand with much rapidity, being enabled to do so by 

 the play of its innumerable feet. 



(a) South Devon, Mus. Leach. 



(b) No locality. 



(e) Holy Island, Dr. Johnston. 



(d) Holy Island, Dr. Johnston. 



(e) Loch Torridon, Robert M' Andrew, Esq. 



Plate V. Fig. 6. The proboscis of Sigalion boa removed and laid open. 

 7. The head and anterior segments seen from above. 8. The head 

 on the ventral aspect to show the mouth and origin of the palpi. 9. 

 A scale from near the middle of the body. 10. A side view of a foot. 

 11, A bristle from the dorsal ramus of the foot, unjointed, but finely 

 serrulated on one side. 12. Another bristle from the same ramus, 

 slenderer and quite smooth. 13. A bristle from the indentation of 

 the foot between the dorsal and ventral rami. 14. A bristle of the 

 ventral ramus. 15. Another bristle of the same, situated under the 

 former, and consequently next the ground. 



Obs. The Aphrodita arcta of Dalyell (Pow. Great, ii. 1 70. pi. 24. 

 f. 14) may be a species of this genus, but it cannot be defined. 



