1906.] OF SOUTHERN INDIA AND CEYLON. 645 



Halgerda Bergh. 



(See Eliot on Dictyodoris tessellata, in Proc, Malac. Soc. 

 vol. vi. pt. 4, 1905, p. 229.) 



The Boris apiculata of Alder & Hancock probably belongs to 

 this genus, which in my opinion is not separable from Dictyodoris. 

 Several new species have been described lately, of which Halgerda 

 graphica Basedow & Hedley is closely allied to H. vnlleyi Eliot 

 if not a synonym. The genus may be tabulated as follows : — 



1. ^. /brmos« Bergh. 



2. H. ? apiculata (A. & H.). 



3. H. (Dictyodoris) tesselata (Bergh). 



4. H. ivasinensis Eliot. 



5. ff. (Dictyodoris) macidata Eliot; probably 

 the young of H. wasinensis. 



6. H. p)imctata Farran. 

 J 7. H. willeyi Eliot. 



\ 8. H. graphica Basedow & Hedley. 

 9. H. elegans Bergh. 



10. H. rubra Bergh. 



11. H. inornata Bergh. 



Halgerda apiculata (A. & H.). 

 (A. & H. 1. c. p. 122.) 



The type specimen is preserved at Newcastle, but the buccal 

 parts have been extracted and the remains are so dry and hardened 

 that nothing can be added to Alder and Hancock's description. 

 That description, however, which includes the radula, makes it 

 eminently probable that the animal is referable to Halgerda, and 

 the filaments which surmount the tubercles should render it easy 

 of recognition. 



Platydoris. 



To the list of 27 species belonging to this genus given by me in 

 the ' Journal of Conchology,' vol. ii. Oct. 1905, pp. 252-3, may be 

 added two more from the ' Siboga' Collection : — 



28. PI. flamviidata Bergh. 



29. PI. sanguinea Bergh. 



Several of the species described are probably colour varieties. It 

 is remarkable that the ' Siboga' obtained a form undistinguishable 

 from the Mediterranean PI. argo in the Malay Archipelago. 



The chief characters of the genus are the hard and leathery 

 consistency, the flat shape, and the armature of the reproductive 

 organs. The efferent ducts are very thick and strong. The 

 lining is raised into lumps and folds, generally yellow in colour, 

 and in the male branch these lumps are in most species further 

 developed into hard scales bearing hooks. These hooks, however, 

 have not been found in PI. striata and PI. flaimnidata. 



Through the kindness of Prof. Herdman I have been allowed 



