Gatty Marine Lahoratory , St. Andrews. 43 



of the bristles are greatly elongated, and they slope forward 

 rather than backward, projecting on each side as a tine 

 fringe. 



The anterior hooks are similar to those of Chone fauveli, 

 though smaller, the posterior part of tlie crown is less 

 rounded, and the three or four teeth above it very sharp. 

 The posterior hooks, while generally resembling those of 

 the common species, have somewhat higher crowns, five to 

 six teeth being clearly visible above the great fang. The 

 posterior part of the crown is also less rounded, as is the 

 posterior outline. The main fang is proportionally shorter, 

 since its point does not project beyond the line of the prow. 

 Another feature is that the crown with its small teeth is on 

 a level with the outer surface of the main fang, whereas in 

 C. fauveli the four large teeth above tlie main fang fit into 

 a convex outline. The figure of Langerhaus *, though poor, 

 clearly indicates the species. 



Chone reayif, sp. n., the sixteenth form, comes from 

 Shetland, off the coast of Ireland, and from the Channel 

 Islands. 



The cephalic plate has a thinner but fuller collar than in 

 Chone fauveli, and its edges are turned in dorsally, sloped 

 inward and backward to be fixed to the first segment on 

 each side ot* the middle line and to the sides of the groove in 

 front ; but its anterior margin is well behind the free edge 

 of the collar above, and no continuation of this part occurs 

 in front — a distinctive feature with such as Chone duneri 

 and others. As in the former species, the fissure presents 

 a pouch at the attachment of the collar posteriorly. The 

 collar passes with a slightly crenate margin nearly straight 

 to the ventral surface, but from attachment the free rim is 

 there narrow. The pedicle of the branchice does not project 

 beyond its edge. In this species the bases to which the 

 branchiae are attached are different, for they form two semi- 

 circular soft grooved lobes, which do not project beyond 

 the margin of the collar in lateral view. To the inner 

 (median) or straight edges the tentacles are attached, and 

 the whole base is constricted posteriorly, so that it is 

 mushroom-like. There is no bifid process of the lip- 

 membrane as described by Southern in Chone filicaudata. 



Each branchial filament has a large camerated chordoid 



* Zeitsch. f. w. Zool. Bd. xxxiv. p. 114, Taf. vi. fig. 34. 



t Named after Lord Reay, K.T., who has so long taken an interest in 

 the marine work at St. Andrews, and who auspiciously opened the <:}attv 

 Marine Laboratory in 1896. 



