164 j\otes from the Gatfi/ Marine Laboratory. 



the bristles, and thus appears to be somewliat shorter than 

 in H. marphys<B. A slight eminence below the cirrus gives 

 origin to the pale dorsal bristles which radiate froui it in a 

 fan-like manner, but when compressed laterally show a 

 shorter, stouter, upper, and a longer, more slender inferior 

 series. The ujjper shorter forms are boldly curved and 

 serrated on the edge. The more slender inferior bristles 

 are less curved and i[\v serrations on the hair-like tip 

 are minute. A sjjine pierces the lower margin of the 

 elevation from wdiich the bristles emerge — in lateral view. 

 These bristles thus closely resemble those of H. marphysos^ 

 differing only in the more minute serrations of the tips 

 and their smaller size. The inferior division of the foot 

 forms a cone with a pointed tip, up to the base of which the 

 powerful spine goes. Its dorsal outline is sinuous, the 

 ventral convex (in lateral view), the outline thus differing 

 from tiiat of H. murphysce, though the !<ize in the respective 

 cases has to be remembered. The upper two have elongated 

 simple tips with only a sligjit swelling above the shaft and 

 very minute serrations on the edge. Those in lateral view 

 are above the spine. Those below the spine have shorter 

 tips, longer rows of spikes, and bifid tips, and the swelling 

 above the shaft is more distinct. The short ventral cirrus 

 has an enlarged base which rapidly tapers to a slender tip, 

 and its surface has a few clavate papilla:;. Posteriorly all 

 the parts of the foot are diminished, and the bristles are 

 proportionally more slender and elongated. 



The scales have the colour mentioned by Mr. Arnold 

 Watson, and a similar outline to those of //. marphysee, but 

 they are thinner and more translucent ; moreover, in some 

 no papillae can be observed. In other scales the papillae, from 

 ten to twenty in number, form a small compact group on the 

 thinnest margin of the scale and about its middle, whereas 

 in H. inarphjjs(e these [)apillae stretch in the adult female as a 

 long band to the angle of the thin edge. The changes here 

 indicated may be the result of growth, hut there is a decided 

 divergence. 



f )n the whole, this Polynoid closely approadies H. mar- 

 physcB, but the structure of the shorter head with its larger 

 eyes, and the closer approiich of the anterior to the posterior 

 pair, the slight differences in the structure of the feet and 

 the bristles all combine to cause hesitation. Intermediate 

 examples, however, may yet enable future observers to unite 

 them. It is an interesting fact^ hoMcver, in connection with 

 the ripe H. marp/iyscs, that a marked change in the condition, 

 of the feet accompanies reproduction, though the eyes 

 remain as minute as before. 



