118 OPHIODROMUS FLEXUOSUS. 



Habitat. — Dredged somewhat frequently on a bottom of tenacious grey clay and mud 

 in 4 — 8 fathoms in Lochmaddy, and especially in Ardmaddy Bay, and one or two were 

 found at the verge of extreme low water in the same bay under an immersed stone and 

 in sandy mud whilst digging for littoral annelids; on old oyster-beds and amongst 

 tangle-roots in 5—7 fathoms in West Voe, Scalloway, Shetland; 100 fathoms in St. 

 Magnus Bay, Shetland (Dr. Gwyn Jeffreys) ; 80—110 fathoms off the coast of Ireland, 

 and in 15—20 fathoms in the Bay of Gralway, in the 'Porcupine' Expedition of 1869, 

 on a bottom of muddy sand with pebbles; 9—125 fathoms 50 miles west of Valencia, 

 Ireland (Dr. Gwyn Jeffreys); 81 fathoms off Cape Finisterre, 'Porcupine,' 1870; 

 Station IV, bottom, Moray Frith, July, 1894 (Dr. H. C. Williamson). 



Extends to Norway (Sars), shores of France, Mediterranean. Burrows of Synapta on 

 the shores of France (Perez). 1 



Head (Plate LVIII, fig. 12) small, distinct, with four eyes, the anterior being 

 somewhat larger and wider apart, and sometimes elongated transversely. Tentacles 

 three, a lateral on each side and a median somewhat shorter. The palpi have a thick 

 basal region, the distal being slender and tapering so that the structure resembles a 

 church spire. 



Body 2J inches long, dilates behind the head, attains its maximum about the anterior 

 third, and then tapers to the tail. It is thus fusiform. The tail terminates in two long 

 slender cirri which are shorter, however, than those of the fourth foot from behind. The 

 first four segments bear modified limbs in the form of long cirri. The dorsum is of 

 various shades of lustrous brown, whilst a whitish streak running backward from the 

 central tentacle divides the head into halves. The dorsum is transversely banded at 

 intervals with belts of fine iridescent blue, the bands extending to the tips of the feet. 

 In a specimen 2J inches long there were a dozen conspicuous belts, besides less evident 

 minor streaks posteriorly. The body-line at the base of each foot has a patch of the 

 same colour, continued across the rugse of the segment in fine blue lines, but they vary in 

 different specimens. The head in some has the same fine bluish colour. The ventral 

 surface of the body is dark madder-brown. When placed in spirit OpModromus loses 

 its tints in a moment, and generally breaks into several pieces. The same result happens 

 on immersion in impure sea- water. 



The proboscis is large (Plate LVIII, fig. 13), devoid of jaws or papilla, and in 

 extension it becomes cylindrical, or has a swollen base and a distal rim. The buccal 

 orifice is capable of great dilatation. 



The body is garnished at each side with long resplendent tufts of bristles which 

 glance with all the varied hues of the rainbow, while from each foot two long hair-like 

 cirri project. The elongated foot is distinctly biramous (Plate LXIX, fig. 13), thus differ- 

 ing from all the Hesionidso except Schmarda's Girrosyllis (Pseudosyllis, De Quatrefages) 

 and (Ersted's Cast alia. The dorsal lobe (a) consists of the long cirrus (b), which springs 

 from a basal segment (ceratophore), and tapers slightly towards the tip, and of the 

 setigerous division, which tapers, as a slender process, outward to a point and envelops 

 the spine. From the upper and posterior part of this division a tuft of slender, elongated 



1 'Proc. Verb. Soc. Sci./ Bordeaux, 1904—5. 



