1901.] ANNELID OJBTAINKD DURING THE "SKEAT EXPEDITION." 81 



-f 138. Nettopus cokomandelianus (Gm.). 



Anas coromandelianus, Gm. S. 'N. i. 2, p. 556 (1788). 

 Nettopus coromandelianus (Gm.), Gates, op. cit. ii. p. 272; 

 Salvad. Cat. Bds, Brit. Miis. xxvii. p. 68 (1895). 

 a, 5. c? $ . Patelung. 30th March, 1899. 



-^-139. Dendeocyona javanica (Horsf.). 



Anasjavanica, Horsf. Tr. Linn. Soc. xiii. p. 199 (Java) (1821). 



Dendrocycna javanica (Horsf.), Salvad. Cat. Bds. Brit. Mus. xxvii. 

 p. 156 (1895). 



a. 2 • Tale Nowy, Patelung. 2nd April, 1899. 

 h. $ . Tremangam, 12th July, 1899. 



7< On a Freshwater Annelid of the Genus Bothrioneuron 

 obtained during the " Skeat Expedition "' to the Malay 

 Peninsula. By Frank E. Beddard, M.A., F.R.S. 



[Eeceived January 14, 1901.] 

 (Text-figures 8-10.) 



There are at present only two species of this peculiar genus of 

 Tubiflcidse known : they come from such widely separated localities 

 as the neighbourhood of Prague ^ and the neighbourhood of Buenos 

 Ayres ^. 1 believe that the facts ascertained from an examination 

 of specimens from the Malay Peninsula justify me in the creation 

 of a third species. 



The worms are of about the same size as average specimens of 

 Ttihifex nvidorum, and thus present no divergence from the two 

 other species of Botlirionmron, 



The prostomium is conspicuous and of the ordinary form that 

 it exhibits among the Tubificidse, as will be seen from an inspection 

 of the two drawings (text-fig. 8, A, B, p. 82). 



Prostomial sense-organs. — I find in the present species the same 

 prostomial sense-organ which I described and figured (in section) 

 in Bothrioneuron americanum. It is, moreover, also unpaired iu 

 the present species. The position of the organ, however, varies : 

 it is usually on one side, which is preferably the left, just at the 

 junction of the convex upper surface of the prostomium with the 

 lower surface. In one specimen, however, it is exactly in the 

 middle of the lower surface, and in another it is as distinctly upon 

 the upper surface, and also fairly median in position. The organ 

 is very decidedly upon the prostomium itself; it is not situated at 

 the junction of the prostomium with the peristomial segment, as 

 is the case with the corresponding organ of B. americanum. 



The one specimen in which the sense-organ happened to be 

 ventral in position is shown in the accompanying drawing, by 



1 Stole, " Mon. Ceskych. Tiibificid.," Abh. Ges. Bohm. (2) vii. p. 43. 

 ^ Beddard, Hamburg. Magalh. Sammelreise, Naiden &c. p. 6. 

 Proc. Zool. Soo.— 1901, Vol. I. No. VI. 6 



