156 Prof. Mcintosh's Notes from the. 



continue to the posterior end, both divisions having a few 

 slender tapering bristles, -wliich are more conspicuous than 

 in front. So far as observed, the hooks of the dorsal division 

 posteriorly are slightly more slender and less curved than 

 those in the ventral. 



A small form (young ?), di^edged off Shetland by Dr. Gwyn 

 Jeffreys in 1867, presents the peculiarity of having only two 

 eyes, and the head shows less of a basal constriction than is 

 usual in examples of C. cirraius of the same size. The 

 complete tentacles of the fourth segment are of very great 

 length, probably reaching in life beyond the tip of the tail, 

 "nhicli has a ventral papilla similar to that of C, cirratiis. 

 The tenth foot has dorsally a long slender tuft of finely 

 tapered bristles, whilst the ventral bristles are much shorter 

 — the flattened tips being expanded like a "bellied"^ knife, 

 and then tapered to a fine point. The hooks by-and-by 

 appear in both ventral and dorsal divisions, and their 

 shape corresponds with that of the ordinary examples of 

 C. cirratus. De St. Joseph * found that in the young of 

 C. tentaculatus of 12 mm. the crotchets appeared in the 

 tenth segment ; but the structure of the bristles and hooks 

 of this form differ from those of that species, not to allude 

 to the structure of the head. Keferstein's Cirrutulus hi- 

 ■ocidatus t differs in the shortness of its tentacles, in the 

 structure of the hooks, and in the nature of the caudal 

 region, which has two cirri. Too much reliance, liowever, 

 cannot be placed on the representations of the minute struc- 

 ture of the bristles at that period. 



Bodecaceria concharum, CEst., is common under the roots 

 of tangles [Laminaria digitata), especially when these have 

 a crust of Lithothamnion beneath them ; occasionally in 

 sandstone, as at the West Rocks, St. Andrews. 



In this the dull greenish head is more attenuated than the 

 rest of the body, the anterior border being rounded, though 

 capable of various changes of form. The colour is brownish 

 red anteriorly, greenish yellow posteriorly, and streaked 

 longitudinally with the red blood-vessel, Some have touches 

 of orange. They dye spirit green. The mouth opens a 

 little behind the tip inferioi'ly as a Y-shaped slit in which the 

 action of the cilia is marked, and with a considerable amount 

 of dark pigment on the lips. The body is about an inch in 



« Ann. Sc. Nat. 8^ ser. t. xvii. p. 50. 



* Zeitsclir. f. wiis. Zool. Bd. xii. p. 121, Taf. x. f^gs. 23-27. 



i 



