232 Illustrations in British Zoology : — 



Lyc6ri5 margaritacea is common in our bay, where it 

 lurks under stones, between tide-marks. It is evidently car- 

 nivorous ; and, between the mandibles of the specimen which 

 served for our figure, a small Gammarus was found in a fatal 

 grasp. Fresh water is an instant poison to it. 



I have been induced to select this worm for illustration in 

 preference to many others, since it gives me an opportunity 

 of correcting several errors which I have committed when 

 describing the same species in the fourth volume of the 

 Zoological Journal, It is there stated that I had not observed 

 the proboscis to be divided into two joints, which, however, 

 is the case ; and the patches of prickles round the base of the 

 mandibles are described as being four instead of six in num- 

 ber. I have there also constituted a species under the name 

 of Lyc6ri5 vlridis, which, a longer acquaintance with this 

 family satisfies me, is merely a variety of the present, of a 

 deeper and more uniform green than usual ; for the character 

 on which I mainly rested the distinction between them 

 (namely, the first segment being striated longitudinally in 

 one, and spotted in the other) is, as I now find, one of no 

 value. To acknowledge errors of this kind is a paramount 

 duty *, although it may prove him who commits them to be 

 one of little tact and experience. 



The following synonymes are, I think, referable to this 

 species : — 



N^ei* caerulea, Pen. Brit. Zool. vol. iv. p. 93. t.27. fig. sup., Turt. Lin. 

 vol. iv. p. 88., Turt. Brit. Faun. p. 135,, Stew. Elem. vol.i. p. 390., Bosc 

 Vers, vol. i. p. 170. Nerei* margaritacea, Leach in Supp. Encyc. Brit, 

 vol. i. p. 451 . t. 26. Lycori* margaritacea, Lamarck Anim. s. Vert. vol. v. 

 p. 312., Johnston in Zool. Journ. vol. iv. p. 420. [and now in Mag. Nat. 

 Hist. vol. vii. p. 233.], Stark, Elem. vol. ii. p. 139. L. viridis, Johnston 

 in Zool. Journ. vol. iv. p. 419. 



Berwick, Dec. 4. 1833. 



* Entertaining this opinion, I could have wished that the correction of 

 one or two similar, but more gross, errors of mine had been made, long 

 before this time, in the same journal in which they originally appeared ; 

 and as it is now apparently discontinued, I may here be permitted to state 

 that the Galba marina of Zoo/. Journ.y vol. iii. p. 321., is the larva of a dip- 

 terous fly, whose ova are frequently deposited and hatched amidst the 

 roots of sea-weed that has been cast ashore ; as Mr. MacLeay proved, in an 

 unpublished letter to the editor of the journal just referred to^ very shortly 

 after the publication of the error. 



Mr. MacLeay is of opinion that my Campontia eruciformis (Zool. Jotcm., 

 vol. iii. p. 325.) is a similar larva; but I am still unsatisfied on this point, 

 for I find it at all seasons at the roots of Confervas in pure sea water. 



Z/umbricus pellucidus (Zool. Journ., vol. iii. p. 327.) is a larva, as I long 

 ago stated. 



Palmyra ocellata (Zool. Journ., vol. iii. p. 329.^ is a young individual of 

 the Polynoe imbricata, accidentally deprived of its dorsal scales. 



