Oatly Marine Laboratory, St. Andrews. 163 



animal. A median streak occupies the centre of the dorsum 

 and another the mid-ventral line. Apparently three achiB- 

 tous segments follow the head, the third and broadest being 

 tessellated or crenate ventrally as well as dorsally, the latter 

 surface being so broad as to reach the area of the next 

 segment toward the middle line, the lateral region being 

 occupied by the elongated scar for the tentacles, only traces 

 of which are present in the examples. The outer edge of 

 each tentacular area abuts on the prominence of the dorsal 

 division of the first bristled foot, which occupies a dorso- 

 lateral position, the dorsal divisions of the succeeding feet 

 forming a well-marked oblique ridge on each side and 

 causing the body to appear as if sheathed in the anterior 

 region (snout and achsetons segments). This arrangement 

 is due to the greater distance between the dorsal and ventral 

 divisions of the first feet, the oblique region including about 

 fifteen feet. Thereafter the dorsal and ventral divisious 

 approach more closely, the space between them, however, 

 remaining distinct to the posterior end. Each division of 

 the foot carries a tuft of long, pale golden, capillary bristles 

 (PI. VI. fig. 3) issuing from a distinct setigerous process, and. 

 no change in the structure of these organs occurs from front 

 to rear. The dorsal bristles, as a rule, are longer than the 

 ventral and are curved outward and backward, the length 

 being less than half the diameter of the body anteriorly. 

 Each consists of a long basal region or shaft slightly 

 narrowed proximally, remaining of the same diameter for 

 some distance, and then gradually tapering to a fine point. 

 Posteriorly one of the dorsal bristles in each tuft is con- 

 siderably larger than the rest, the tip stretching outward as 

 a long delicate hair. The tips of all, indeed, in this region 

 are very fine. The ventral bristles are shorter and slightly 

 broader, but also have delicately tapered tips. The ventral 

 setigerous processes and tufts are really ventral in position, 

 for in the preparations they are visible only in ventral and. 

 lateral views. 



The structure of the bristles of this form distinguishes it 

 from the Chatozone macrophthalma of Langerhans *, and, 

 moreover, the skin of the species from Madeira is smooth. 

 The Heterocirrus marioni of De St. Joseph f from Dinard 

 has no crotchets, capillary bristles occurring throughout 

 bDth divisions, but the ventral bristle is Hattened at the tip 

 and with a hair-like termination. 



* Zeitschr. f. wiss. Zool. Bd. xxxiv. p 98, Taf. iv. fig- 10. 

 t Ami. Sc. Nat. 8' s^r. t. xvii. p. 56, pi. iii. figs. 62-G4. 



11^ 



