Gatly }fariiie LahoratovT/, St. Andrews. 105 



sixteen separate cirri are filiform. The elongated cirrus is 

 in tlie mid-ventral line. The anal cup is comparatively 

 shallow, witii the anus often on a slight cone in the centre. 

 In two large Ilebridsan examples the cirri of the funnel are 

 all short and twenty-seven in number. In another large 

 form, procured in tlie * Porcupine' off Cape Guardia, the 

 funnel had no long cirrus, the number of cirri is thirty- 

 seven, and the anal [)rocess is conspicuously ridged or folded. 

 A small speciujen from St. Magnus Bay (100 fathoms) had 

 a very long filiform mid-ventral cirrus. Occasionally the 

 vent projects as a conical process, similar to what Arwidsson 

 shows in his P. affinis. 



The hooks have a long curved shaft, tapered at its base 



and dilating as it passes upward to the shoulder, which forms 



a prominent hump posteriorly and a slight one anteiiorly. 



It then contracts to the neck, above which the distal region 



dilates, and ends in a broad heavily armed crown. The 



great fang leaves the throat nearly at a right angle, curves 



slightly downward, and ends in a sharp point. Six to seven 



teeth in a diminishing series occur above the latter on the 



crown. The interior of the shaft is striated, and the striae 



are continued into the neck, where they are somewhat oblique 



inferiorly, but longitudinal toward the crown. The gular 



bristles come off close to the great fang and curve forward 



and upward on each side of it. The anterior hooks differ 



from the typical forms in their shorter and less boldly curved 



shafts, shorter necks which are less dilated distally, in the 



larger angle made by the great fang and the neck, and iu 



their much flatter crowns, three or four teeth only being 



visible behind the great fang, and the gular bristles are 



rudimentary, passing obliquely upward close to the great 



fang. The first hook of the row in the third foot is even 



more rudimentary, as shown by the blunt tip of the large 



fang, the fusion and indistinctness of the teeth on the 



crown, and its short and nearly straight shaft. Such may, 



however, lie an undeveloped or developing form. The hooks 



of the last row (nineteenth) retain much of the typical 



structure, though their shafts are shorter. Five or six 



teeth are visible on the crown above the great fang, and 



the shoulder is largely developed. The bristles of this region 



consist of the two groups, the stronger having narrow wings, 



and the slender forms are i&yv in number and extremely 



attenuate. 



A large thovigh softened and fragmentary example dredged 

 by Dr. Gwyn Jeffreys off the Hebrides in 1866 has hooks 

 ■which differ from the foregoing not only in their great size 



