12 Prof. M'Intosh's Notes from the 



The brancliise are three in number, the anterior being the 

 largest, the second and third regularly diminishing. In 

 proportion to the size of the body they are somewhat larger 

 than in T. nehidosa and they have a stiffer outline. They 

 are dichotomously branched, and have very short terminal 

 divisions — a distinctive feature when contrasted with 

 T. nebulosa. 



The setigerous processes are seventeen in number^ the 

 first occurring close to the base of the last branchiae. The 

 bristles are long, translucent, sliglitly yellowish, and finely 

 tapered, and, as usual, in two series, a shorter and longer. 

 In the latter the wings are narrow and indi:stinct_, in the 

 former they are broader and easily recognized, but they do 

 not proceed to the finely tapered extremity of the bristle. 

 A curvature of the tip occurs at the winged region. Little 

 difference exists between the first bristles and the last, except 

 in the fewer number as contrasted with the middle groups. 



The rows of houks commence on the second bristled 

 segment, and they are comparatively short to the seventh 

 bristle-bundle, the last ten of the region being longer. 

 Moreover, whilst they form a single row in front, they are 

 arranged in a double row posteriorly (eleven to twenty 

 segments, Marenzeller), the great fang in each pointing to a 

 median line between the rows. Behind the bristles tlie 

 hooks are borne on an uncinigerous process or lamella, and 

 form shorter rows than in front. These lamellse have a 

 concave distal margin anteriorly, but posteriorly the tip is 

 bitid, and the processes diminish much toward the tip of 

 the tail. 



The hooks somewhat resemble those of Polymyiia nebulosa 

 in general form, hut are readdy distinguisheiJ by the presence 

 of a second tooth above the great fang and the somewhat 

 shorter base. 



In Polymnia nebulosa, INIontagu, the seventh species, which 

 is found on both sides of Scotland, England, and Ireland, 

 the cephalic region is distinguished by the great size of the 

 upper collar or arch, and by its frilled inward curve at each 

 hower edge. Its upper surface is somewhat flattened, that 

 is to say, only a shallow groove is present, the mass of 

 tentacles springing from the posterior half near the rim. 

 These tentacles are pale orange in life and spotted with 

 white, so as to give them a barred appearance, and their 

 movements are remarkable, for not only do they aid in the 

 construction of the tube, but hoist the animals up the per- 

 pendicular side of a glass vessel or in any direction, and are 



