170 Prof. M'Intosli's Notes from the 



formation. The terminal caudal process has an even (con- 

 tinuous) rim. The first foot is peculiar in having bristles in 

 its dorsal division, which presents a rounded lamella with a 

 setigerous process in front and a small tuft of tapering 

 hristles slightly curved backward in situ. The ventral 

 division has a similar thougli somewhat broader lamella, in 

 front of which is a conspicuons group of longer upper and 

 shorter lower bristles, the latter having distinct traces of 

 wings. The second, third, and fourth feet have completely 

 formed dorsal and ventral divisions. The 5th segment has 

 minute tufts of dorsal and ventral bristles, as in other forms, 

 besides the great hook-like bristles which have the concavity 

 of the tips directed backward, and which are arranged in a 

 cuive. In the ordinary condition" the shaft enlarges from 

 the base upward to the middle, then slightly diminishes to 

 the tip, which forms a lever-lil\e hook with a concavity 

 posteriorly and an excavation in front. The foregoing hook- 

 like bristles are accompanied by a series of spear-sbaped 

 bristles. In the developing hook the distal curve is very 

 marked, and a small shoulder appears at the base of the 

 concavity in front, whilst a lateral dimple and elevation and 

 a differentiation at the commencement of the terminal curve 

 are evident. In frontal view, as Mesnil shows, the distal 

 region is likewise differentiated. Tlie winged hooks com- 

 mence in the ventral division of the 7th bristled segment. 

 Each dilates a very little above the base and has a marked 

 forward curve throughout tlie greater part of its length, then 

 bends backward and diminishes to the neck. The main fang 

 comes ofi" at a considerable angle to the neck and is sharp, 

 but the spike on the crown has a small angle with the fang. 

 The dorsal bristles become extremely slender posteriorly, 

 though of considerable length. Moreover, bundles of bristles 

 even more slender than the foregoing occur in each foot 

 posteriorly and they somewhat resemble linear crystals, being 

 perfectly straight and slightly tapered at each end. The 

 function of these . is unknown. Mesnil states they are 

 extremely caducous, and do not occur ia front of the 80th 

 bristled segment. The bacillary pouches seem to contain 

 only granules somevvhat larger than in Magelona. The 

 branchise commence on the 8th segment, attain their maxi- 

 mum a few segments behind, and then they gradually 

 diminish, the total number being about 35-40. 



A third species appears to approach the Pulydora quadri- 

 lubata of Jacobi ■^. The head has smaller prostomial lobes 



* Anat. histolog. Untersuch. der Polvdoren der Kieler Bucht. 

 Wi^?enfels, 1883, p. 6, Taf. i. & ii. 



