984 MB. W. M. THOMSON ON A BRANCHIATE [Dec. 18, 



own table of genera [5] it is evident that he employs the existence 

 of jaws as a character distinguishing Lepidonotus and Polynoe 

 on the one hand from Aphrodita on the other. If he had 

 followed his own table, he should have put the animal in the genus 

 Polynoe; but the " pili breves, in penicillum crassum " evidently 

 caused him to overlook the existence of jaws. Further, in comparing 

 the diagnoses of the two " families " Aphroditida? and Polynoida?, 

 in the Monograph by Prof. Mcintosh, recently published by the 

 Bay Society, it is apparent that our specimen differs from the 

 Aphroditida? (a) by the possession of lateral tentacles, (b) by the 

 want of a facial tubercle, and (c) by the possession of jaws and 

 papilla? on the pharynx : also (cl) by the want of felt and (e) of 

 the long stiff ventral bristles [6]. On the other hand, the following 

 is Mcintosh's diagnosis of the genus Lepidonotus [7] : — 



" Body short, more or less linear. Anterior part of the cephalic 

 lobe produced into the bases of the median and lateral tentacles. 

 Palpi smooth or with papillae in five longitudinal rows. Three 

 comparatively short alimentary cseca directed forwards into the 

 peripharyngeal space. Elytra 12 pairs, covering the dorsum 

 entirely, and occurring on the segments bearing feet thus : 1, 3, 4, 

 6, 8, and so on to 20, 22. Bristles of the superior lobe slender, 

 serrate, shorter than the inferior, which have a smooth portion 

 below the slightly hooked tip, and then a spinulose region beneath. 

 Nerve-trunks in the granular layer of the epiderm, between the 

 powerful oblique muscles." 



Prom this it is evident that our animal belongs to the genus 

 Lepidonotus, the only point of difference being that the rows of 

 papilla? on the palps are 7 or more instead of 5. 



A comparison of the above account of this worm with that given, 

 in brief and without figures, by Mr. Kirk [8] makes it quite 

 evident that Quatrefages's " A. squamosa " is identical with Kirk's 

 L. yiyanteus ; and it is not to be wondered that the latter author 

 overlooked the description by Quatrefages, as the worm is so 

 palpably not a member of the genus to which he ascribed it. 



Dunedin, Aug. 24, 1900. 



List of Literature referred to. 



1. Eat Lankester. Proc. Boy. Soc. 1873. 



2. "W. Haswell. Proc. Linn. Soc. N. S. W. vii. pp. 255-256. 



3. A. G-. Bourne. Trans. Linn. Soc. Lond. 1883. 



4. Quatrefages. Annelida, vol. i. pp. 201-203. 



5. Id. ibid. p. 186. 



6. W. McIntosh. British Annelida, p. 241. 



7. Id. ibid. p. 273. 



8. T. W. Kirk. Trans. N. Z. Inst. vol. ii. p. 399. 



9. H. Johnstone. Proc. Calif. Ac. Sci. 1897. 



