230 Illustrations in British Zoology : — 



work, namely, in his " Observations Generales sur l*Organis- 

 ation et les Facultes des Pulmones sans Opercule," in generalis- 

 ing on the conditions of the tentacula in various genera, spoken 

 and analogised on the tentacular function of the lips in the 

 genus Testacellus. It is hence apparent that a rich store 

 of facts and observations is already on record on these in- 

 teresting animals ; and, had we been earlier aware of this, we 

 could scarcely have resisted quoting several of the more 

 instructive of them. As it is, we can only thus refer to 

 them *, and express our sincere regret that Ferussac's ex- 

 cellent work is so rare in Britain ; or, at least, in London. 

 See V. 192.] — J. D. 



Art. V. Illustrations in British Zoology. By George John- 

 ston, M.D., Fellow of the Royal College of Surgeons of Edin- 

 burgh. 



19. Lyco^ri5 margarita'cea. (^g. 42.) 



The body of this worm is from 4 in. to 6 in. long, con- 

 tractile, semicylindrical, of the thickness of a large quill, and 

 tapered towards the tail : it is of a brown colour, more or less 

 deeply tinted with metallic green, particularly near the head 

 and on the anterior margins or sides of the segments, and, in 

 certain lights, is finely iridescent. A red vessel runs down 

 the middle of the back, giving off to each foot a small branch, 

 which is again slightly ramified ; and a similar vessel may be 

 traced along the flat ventral surface, which is marked with a 

 central furrow, and stained in some degree with the opaque 

 internal viscera. The head is square, with four small eyes ; 

 two placed on each side at the base of a conical projection, on 



♦ We must just notice the following : — M. de Ferussac, in his ** Ob- 

 servations Generales sur T Organisation et les Facultes des Pulmones sans 

 Opercule," in speaking of the means given to various animals of this class 

 for defending themselves from the heating and drying effects of the solar 

 rays, mentions a manteau particulier which is given to the Testacelli. This, 

 in his generic character of the Testacelli, is thus described : — ** Manteau : 

 simple, gelatineux, contractile, cache habituellement sous le test, divise en 

 plusieurs lobes susceptibles d'envelopper tout le corps par un developpe- 

 ment extraordinaire, lorsque I'animal eprouve le besoin de se garantir de 

 la secheresse." Mr. J. D. C. Sowerby has seen one or more animals enve- 

 loped in this " manteau : " the body is then in its most contracted state. 

 In the dead testacellus, of which we have spoken above, we perceived 

 a starlike scar at a little distance from the front extremity of the body, 

 which we avoided mentioning, for fear of being found in some error. On 

 the organs of generation, however, Ferussac has remarked, " Reunis ; 

 orifice en arriere du grand tentacule droit : '* and this remark, and the 

 subsequent inspection of a preserved specimen at Mr. J. D. C. Sowerby's, 

 assure us that the scar we had seen was this orifice. 



