222 SIPHONOSTOMACE^. 



rounded behind, thick-skinned and corrugated, with very narrow 

 rings. There may be about ten pairs of feet on it. The anus is 

 terminal and puckered, and without appendages. The bristles are 

 alike on every foot ; they are simple, slender and setaceous, and so 

 long that I presume they cannot be entirely retractile. 



The worm is a singular one. When Oersted says that it forms a 

 link between the families Ariciadce and Arenicolidce, he means merely 

 to speak of the character of the branchiae. There is no similarity in 

 form, nor in the structure of the skin ; and there is a great dis- 

 similarity in the ventral disk. Indeed, the form of this, its mus- 

 cular structure, and its deep furrow, associate Eumenia with Ophelina 

 and Ophelia, and is so discriminative, that these genera ought to be 

 removed from Ariciadce, and be formed into a separate group. This 

 can be done only by a naturalist who has to take a survey of the 

 class as a whole, and who is not restricted in his investigations to a 

 single country. 



The specimen described is about 1^ inch long, thick and subcy- 

 lindrical, nearly alike at both ends, which are obtuse. There is some 

 irregular bulging in the body, which arises undoubtedly from con- 

 tractions made in the agony of death. The colour is a dead white. 

 The skin is smooth. The ventral surface is flattish and grooved. 



(a) The Staples, Lieut. Thomas, R.N. 



The " Vermicidus crassus " of Daly ell seems to be allied to this 

 species. He describes the body as " thick, fleshy, smooth, round, 

 tapering to each extremity, extending 21 lines by 4 in diameter. 

 The mouth appeared to be a short slit, widening upwards below the 

 anterior extremity ; and what T was induced to consider as the oppo- 

 site extremity was surrounded by a row of cylindrical fleshy spines 

 of moderate length. The body, apparently round, has a flat narrow 

 belly, whereon the animal crawls, like the narrow sole of the Doris, 

 and of which the edges close and broaden in the same manner. Its 

 cohesion is slight ; the belly occupying about a fifth part of the cir- 

 cumference. The skin was smooth and uniform, without segments, 

 or the least indications of them." Can swim on the surface of the 

 water. — Daly ell, Pow. Great, ii. 88. pi. 10. figs. 11, 12. 



Fam. XII. SIPHONOSTOMACE^. 



Chlorcemea = Chloremiens, Quatrefages in Ann. des Sc. nat. xii. 



277-280(1849). 

 Pherusea, Grube, Fam. Annel. 71. 



Char. Body soft, vermiform, cylindraceous, with similar short 

 segments : head defined or continuous, and, with one or two of the 

 following segments, retractile into the anterior portion of the body, 

 furnished with tentacular filaments : post-occipital segment armed 

 with lateral tufts of bristles projecting forwards and often beyond the 



