52 Prof. M'Intosli's Notes from the 



bristles tlie uncinig;erous rows become slightly more promi- 

 nent, and soon form conspicuous ventro-lateral processes 

 almost to the tip of the tail. The hooks, which are uniform 

 in structure throughout (PI. II. fig. 9), are characterized by 

 the elevated crowns, with four or five sharp teeth above the 

 great fang, a convex dorsal outline and a deep incurvation 

 above the base, the posterior angle of which has a well- 

 maiked process ; the inferior outline is convex, whilst below 

 the great fang is a prominent process from which the outline 

 slopes to the prow. 



Artacama canadensis^ sp. n., is not uncommon in water of 

 some depth in the Gulf of St. Lawrence. Hitherto the genus 

 lias been found chiefly in northern latitudes, such as Spitz- 

 bergen and Norway, and has not been met with in the British 

 area. It is distinguished by its builious and symmetrically 

 rugose buccal region, from which the everted proboscis in 

 some cases projects as a papillose globular mass with a con- 

 spicuous cone at the apex. The cephalic plate is peculiar, 

 for it is produced posteriorly into two lobes, rounded distally, 

 whilst its ventral margin forms a frilled funnel, considerably 

 elevated above the mouth, though the arrangement of tlie 

 parts corresponds with species in which the mouth is in the 

 central part of the frills ventrally. Tlie plate has a distinct 

 dorsal collar. 



The body is enlarged anteriorly, the snout being somewhat 

 bulbous, and tapered posteriorly to a slender tail with a 

 terminal anus. It is rounded dorsally, flattened and grooved 

 ventrally, and the segments are distinctly marked, tlie 

 anterior having two rings and the posterior three in a large 

 example. Eight of the anterior segments, ventrally, have 

 wide glandular belts, and thereafter are five central glandular 

 shields. In a small example with a complete posterior end 

 the terminal segments appeared to be only two-ringed, and 

 finally only a single ring characterized the nine or ten 

 segments. 



The branchiae are iu three groups on the second, third, and 

 fourth segments, and their filaments are smaller than in such 

 as Thelepus. Each springs from a central point, from which 

 the twenty or more filaments diverge, and when torn they 

 adhere by their bases. 



The anterior region bears seventeen pairs of setigerous 

 processes, which are flattened lamellse with oblique distal 

 edges, the dorsal being the most prominent, whilst the 

 anterior lip projects beyond the surface. They bear two 

 series of pale golden bristles, viz. a longer and a shorter. 



