278 MMADM. 



worth's May. Nat. Hist. i. 279) ; but, in truth, his remarks are 

 very irrelevant, and deserve no consideration. Milne-Edwards, on 

 the contrary, adopts our original view : — ** Ce singulier animal a etc 

 decouvert sur les cotes de I'Angleterre, par M. Johnston, et ne serait 

 suivant M. Macleay qu'une larve de quelque insecte diptere, mais 

 ay ant eu 1' occasion de T observer a I'etat vivant, dans la rade de 

 Toulon, nous ne croyons pas devoir adopter cette opinion, et nous 

 sommes portes a considerer ce genre comme etablissant le passage 

 entre les Nereidiens et certains Helminthes." 



Fam. XIX. ?M^ADiE. 



1. MJEA. 



1. M. mirabilis. Plate XXII. 



Besc. Worm slender and filiform, of the thickness of common twine, 

 and about 4 inches long, soft, distinctly annulated, of a wood-brown 

 colour, with dark specks in clusters along the sides. Head distinct, 

 serpent-like, flattened above, obtusely pointed, scooped underneath ; 

 the mouth inferior, about a line from the apex, furnished with a 

 thick, short, subglobular, smooth proboscis. On each side of the 

 mouth at its base, and external to it, there originates a long filiform 

 tentacular appendage, which is fully as long as a third of the total 

 length of the body : they are jointed at not very regular intervals, 

 and naked at the root, but, at a little distance upwards, they begin 

 to be fringed, on one side, with short cylindric obtuse fleshy cirri, 

 in two close-set series, which extend to the very apex. The rachis 

 of the filaments is minutely crenulated on the opposite edge, and it is 

 furnished with numerous dark minute granules, collected, principally, 

 at the origins of the cirri. Thorax of nine segments, of which eight 

 are equal and similar, about twice as long as their diameter, cylin- 

 drical, and distinguished by having a vesicular lobe at the base of 

 the bristles, which are collected into fan-shaped fascicles projecting 

 forwards. The bristles in each fascicle are numerous, unequal, 

 simple, setaceous, flexuous, with a long sharp point, smooth. The 

 ninth segment is thoracic, but it is smaller than its antecedents, with 

 larger lobes at the base of the bristles. Abdomen elongated, cylin- 

 drical, the segments twice as long as their diameter, each furnished 

 on the sides with a roundish cluster of dark hard granules, and with 

 four fascicles of retractile bristles placed equidistantly. The bristles 

 are simple, smooth, of a straw-yellow colour, rather stout and fur- 

 cate, being also bent considerably towards the apex. There are 

 about eight in each fascicle, and they are shorter and stouter than 

 those of the thoracic feet ; nor have they the lobe at the base, or only 

 in a minor form. 



This singular worm was given to me by Dr. Greville, who does 

 not remember the locality in which it was found. He got it, he 



