Galfy Marine Laloratorij, St. Andrews. 39 



From the Zctlandic seas comes the twenty-third form, 

 Lysilla loveni, Malmgren. la this the cephalic plate passes 

 forward from a small dorsal collar and is thrown into various 

 folds, the edges of which appear to be somewhat thinner than 

 in Polycirrus, and hence show a more elegantly frilled 

 margin. Ventrally the plate forms a broad flap fixed later- 

 ally, but with the inner edge (and flap) free. The surface 

 is covered with numerous clavate and grooved tentacles, but 

 the ventral flaps have clusters of more minute filiform ones. 

 The mid-ventral region behind the mouth has a large and 

 prominent tongue-shaped process — smoothly continuous 

 with the oral surface anteriorly, where it is fixed ; it is free 

 and somewhat conical posteriorly. In lateral view it forms, 

 indeed, a spout-like process at right angles to the body with 

 an elevation (glandular) in the centre. 



The body is enlarged anteriorly and marked by the two 

 lateral rounded bands, minutely tuberculatcd and ringed, 

 the largest tubercles or papillae being on the ventral surface 

 of the longitudinal bands. The segments are not distinctly 

 defined, except by the setigerous processes in front ; but 

 Malmgren states that the posterior region (absent in the 

 British example) presented about twelve deep sulci. He 

 gives the length of 30-50 mm., and the width of the tumid 

 anterior region as 5-6 mm., that of the posterior part 2- 

 2-5 mm., and the latter, though minutely ringed, is smooth. 



Six setigerous processes occur anteriorly in the groove, 

 though no bristles are visible under a lens. Each consists of 

 a slightly conical process with a curved tip, and presenting a 

 white streak in the interior due to the bristles, which consist 

 of a single closely arranged fascicle of simple translucent 

 bristles, which curve distally in conformity with the outline 

 of the process and end within the tissues at the tip. Except 

 for stiflening the setigerous processes, these bristles are thus 

 devoid of function. 



In Trichobranchus glacialls, Malmgren, the twenty-fourth 

 form_, the cephalic lobe ditt'ers irom that of Polycirrus in its 

 reduced condition. Dorsally it has a groove separating it 

 from the first segment, and is provided with two eye-spots, 

 the lobe then projecting forward as two symmetrical rounded 

 bosses flauked on each side by a translucent free flap. From 

 the surface springs a dense series of tentacles — filiform and 

 fissiform. The filiform are pale pink in colour and — like the 

 larger, clavate, grooved, red-streaked ones — keep up a con- 

 tinuous movement. The translucent lateral flaps are devoid 

 of tentacles. The distinction between the three groups of 



