2135 APPENDIX. 



tion afforded, he says, an opportunity of giving a very complete description. He follows Prof. 

 Keferstein in his classification, and therefore the observations on this head in the " Zoography" 

 are equally applicable here. He is also rather behind date in his remarks on the value of the 

 stylet -region in the discrimination of species. 



In what he calls the granular coat of the skin he found small brilliant bodies, sometimes in 

 the form of prisms, sometimes in the form of buckles. This peculiar condition has not been 

 observed in the British Nemerteans. Only longitudinal muscular fibres were present in his species, 

 but he does not say that he made any transverse sections. In consonance with the .structure of the 

 Enopla, to which the form belongs, there ought to be external circular as well as internal longitu- 

 dinal fibres. I cannot agree with his proposition that naturalists generally consider the proboscis 

 an organ of offence and defence, for observations on the living animal, and the anatomy and phy- 

 siology of the organ in both Enopla and Anopla, render this view quite theoretical. He is safe, 

 however, in objecting to the interpretation of his countryman, M. Leon Vaillant, previously 

 narrated. 



A vital discrepancy is the affirmation that the mouth in his species (one of the Enopla) opens 

 behind the ganglia, because in every example (British and foreign) of this group seen by me the 

 position of the oral orifice is quite in front of the ganglia and ganglionic commissures, and thus, 

 very properly, forms one of the most important distinctions between them and the Anopla, in 

 which (latter) the mouth invariably opens behind the ganglia. As an accompaniment tp this 

 erroneous view the author has quite overlooked the characteristic oesophagus, which forms a lon- 

 gitudinally plaited ciliated sac (essentially differing in appearance from the rest of the digestive 

 chamber) behind the ganglia. The oral slit shown in his figure might pass for one of the longi- 

 tudinal rugae of the organ. It is by no means easy to arrive at an accurate knowledge of the 

 anatomy of these animals, and hence the greatest care and patience are necessary. 



He further observes that the proboscis is fixed to the wall of the " general cavity of the 

 body," a position it does not occupy, since it is enclosed in its special sheath of two coats, and to 

 the inner surface of which the terminal ribands are duly fixed. M. Marion's interpretation 

 implies a total want of this sheath, which, I am sure, a single transverse section would at once 

 render apparent. He next narrates that the anterior region of the proboscis is covered with 

 papillae, but he would have been more exact if he had mentioned that these organs are internal, 

 for on glancing at his figure (PI. 17, fig. 3, op. cit.) it is difficult to say whether they are wholly 

 internal or also common to the external surface. To have got the figure the organ must have 

 been turned inside out at its anterior part. The basal apparatus of the central stylet is described 

 as brownish. It is only so by transmitted light — from the dense mass of white granules. The 

 terminations of the ducts of the marginal stylet-sacs have never, in any form observed by us, 

 been close to the aperture for the central stylet in the floor of the anterior chamber, but at some 

 distance therefrom. The statement, also, that below the stylet-sacs the fibrous tissue is furnished 

 with fine pigment-granules is not sufficiently comprehensive, Tor no mention is made of the 

 regularly arranged circlet of granular glands (?r in our figures), neither is any help on this point 

 obtainable from the plate. 



Another discrepancy is the arrangement of the duct from the reservoir (his jpoclie de reserve 

 du liquide venimeuw), which canal he describes and figures as extending forward to open into the 

 floor of the anterior chamber near the point of the central stylet. If the author had watched an 

 organ under careful pressure he would have seen the granular gland-cells from the posterior 



