240 REPORT — 1851. 



results of the inquiries of QErsted and those obtained through the author's 

 investigation are so striking and irreconcileable, that one or other of them 

 must be egregiously false. Rathke has published descriptions of what he 

 announces as new species of NemertinidcE. As our desire is in this place only 

 to refer to sucli points of structure as relate to the alimentary system, it is 

 necessary merely to report, with reference to the descriptions of M. Rathke, 

 that some of the diagnostic characters are thus given. "At the anterior 

 margin of the body a small opening was found which Rathke did not regard 

 as a moutli, which lies further down on tlie abdominal side, and is represented 

 by a large longitudinal cleft. On the right and left of the anterior end of 

 the body is a boat-shaped, superficial, longitudinal furrow, to which a strong 



bundle of nerve passes from the red ganglion of the brain The 



intestine, running out straight at the posterior end of the body, contained a 

 whitish slimy fluid, from which circumstance thi<: author conjectures that the 

 worm sucks its nourishment from other white-blooded animals, as a great 

 number of small, thin, cuticular sacs, which were attached in a single row, 

 behind each other, on the inner side of tlie body of this worm, contained in 

 some individuals distinct eggs, and in others sperm-cells. Under the dorsum 

 runs a very long snow-white and spiral canal, which is very muscular, and 

 lies bulged out like a proboscis at the opening first mentioned. Rathke con- 

 fesses that he could not succeed in determining its use." 



By Ehrenberg it is held that the part described by the preceding authors 

 as an alimentary canal is really an egg-passage, while he regards the white 

 spiral organ as the alimentary canal. Enougli has been cited historically, to 

 convey to the comparative anatomist some conception of the chaos and dark- 

 ness which brood over the problem of the organization of this genus of An- 

 nelids. The observations of Mr. H. Goodsir* on this subject must not be 

 omitted. By this author a description of two species of Nemertinidce is pub- 

 lished, one under the name of Serpentaria, the other under that of Nemertes. 

 With reference to the former species, Mr. Goodsir observes that the anterior 

 extremity of the body is pointed, with the proboscidean orifice obscure and im- 

 perfectly developed; the male generative apertures on each side, and the cloaca 

 on the abdominal surface immediately behind. Mr. Goodsir further states, 

 that as the animal has no true proboscis, the proboscidean orifice is very 

 small or imperfectly formed, which renders it difficult to be seen. On each 

 side of the rostrum there is to be seen a longitudinal narrow slit, generally 

 closed, and communicating with the male generative system. Immediately 

 behind these, and on the abdominal surface, is another larger orifice, which 

 the animal has the power of opening and shutting at pleasure. When open it 

 is of an ovoid shape. The edges are serrated. This leads to a large longitu- 

 dinal cavity which runs through the whole length of the body, but lor a 

 considerable extent anteriorly is continuous and very much dilated ; in the 

 remainder of its extent it is more confined and interrupted by the ovaries 



non vero nervi (?). Oculi 2, 4, 6, 8, 10. Multi vel nulli. Orgaiia respiratoria specialia nulla, 

 vel fissurse respiratoriae laterales in capite aquae ad cordum parietes aditum concibantes. 

 Circulatio completa et corda duo. Tubus cibarius simplex cum oris apertura infera (rarius 

 terminali) et ano teniiinali. Os nullum exsertile. Sexus duo, in utroque orgauum copula- 

 tionis stimulandoe. Testiculi et ovaria cava ne minimum quidem forma inter se discrepantia 

 tantum modo contento (ovuUs aut spermatozois) complura in utroque latere uniuscuj usque 

 segmenti." It will be found that this diagnosis corresponds in no essential point with the 

 statement given in the text of the anatomy of Nemertinidie ; and, moreover, the inaccura- 

 cies into which Oersted has fallen exemplify the importance of resting all ' diagnoses ' on 

 carefully instituted dissections. Anatomy alone should be the basis of all correct specific 

 descriptions. 



* Annals and Magazine of Nat. Hist., June 1845. 



