AMYTIACE.E. 197 



cirri none : feet uniramous, with a dorsal moniliform cirrus, a small 

 setaceous ventral cirrus, and two brushes of bristles on the setigerous 

 lobe : bristles compound, with the terminal piece falcate. 



Obs. This new genus is allied to Syllis, from which it differs in 

 the number of eyes, in the absence of tentacular cirri, and in the 

 appendages to the feet ; the Syllis having two cirri to each and a 

 single bundle of bristles, while the loida has one cirrus and two 

 bundles of bristles. 



Perhaps the Noctiluca marina of Adler, in Linn. Amcenit. Acad. 

 iii. p. 202. tab. 3, might be referred to this genus. It is only two 

 lines long, and is a native of the Indian Ocean. 



1. I. macrophthalma. Plate XIV. fig. 5. 



loida macrophthalma, Johnston in Ann. Nat. Hist. iv. 231. pi. 7. f. 5. 

 Hab. The coralline region. 



Desc. Worm about an inch long and a line in breadth, of a dark 

 blue or purple colour, unspotted, linear-elongate, depressed, smooth. 

 Head small, but very distinct, pale, rounded in front, entire. Eyes 

 two, very large, lateral and nearly marginal, prominent, dark brown. 

 Antennae three, frontal, filiform, rather short, equal in size and 

 equally distanced, porrect, faintly annular. Segments twenty-five in 

 the specimen examined, distinct, broader than long, the post-occipital 

 and anal considerably less than the others and with proportionably 

 small appendages. Feet papillary, uniramous, each armed with a 

 dorsal cirrus twice as long as the foot, obscurely moniliform, colour- 

 less, and with two bundles of bristles, the superior bundles consisting 

 of short stout retractile bristles, jointed near the top, and with a 

 spine in their middle ; the inferior bundles of very long setaceous 

 unjointed hairs, which the worm has no power of withdrawing. The 

 first pair of feet is destitute of this inferior bundle. The anal ex- 

 tremity was wanting in the only specimen I have yet met with, but 

 from the reparation which had begun, I believe it to be terminated 

 by two styles similar to the dorsal cirrus. 



Plate XIV. Fig. 5. loida macrophthalma. 



Fam. IX. AMYTIACE^. 



Amytidea, Grube, Fam. Annel. 63. 



Char. Body vermiform or linear, more or less flattened, indented 

 at the sutures, consisting of comparatively few segments. Head 

 connate apparently with the post-occipital segment, with from four 

 to eleven tentacular filaments (partly tentacula and partly tentacidar 

 cirri) ; and one or two pairs of eyes : mouth with a ventral aspect. 



