376 SIR C, ELIOT ON NUDIBRANCHS [DeC. 1, 



larger than the others. The branchiae are six, tripinnate, veiy 

 ample and delicate. The tiifts at the side of the posterior pair are 

 almost separate, so that the whole number might be reckoned as 

 eight. The rhinophore-pockets are closed by indistinct crenula- 

 tions. The oral tentacles are of a fair size, white and conical. 

 There is no trace of labial armature. The radula foi-mula is about 

 48 X 60.0.60, The teeth are simply hamate, the innermost smaller, 

 the two or three outermost iri'egular. The penis is armed with 

 the hamiferous disks characteristic of the genus apparently set in 

 four rows, and the vagina provided with strong folds. 



The animal, both when alive and when preserved, is exceedingly 

 hard and rough. It is very sluggish, and I have always found it 

 fitted into crevices on the underside of stones, as if it had not 

 moved for a long period. 



20. Platydoris FORMOSA ? (A. &, H.), var. 



[Alder & Hancock, " Notes on a Coll. of Nudibr. Moll, made in 

 India," Tr. Z. S. iii. 1864, p. 116.] 



One specimen from Chuaka. 



The notes on the living animal describe it as bright scarlet, 

 shaded in places by minute bi'own specks, vei-y flat, and rough to 

 the touch all over. The end of the mantle had been thrown oflf, 

 probably by self- mutilation, so that the body terminated abruptly 

 behind the gill-pocket. 



The alcoholic specimen is much bent, but if straightened out 

 would be about 5 centimeti'es long ; the maximum total breadth is 

 4 and the maximum width of the mantle margin 1-4. The some- 

 what projecting I'hinophore-pockets have slightly crenulate edges, 

 as has also the branchial pocket, which is neai-ly round. The 

 branchiae are six, tripinnate, and rather small. The foot is some- 

 what broader than usual in the genus, grooved and notched in 

 front. The oial tentacles are lai-ge and slightly grooved on the 

 outer side. The buccal mass is very laige and mviscular. There 

 is no labial armature but a large dark radula, consisting of simply 

 hamate teeth, the innermost smaller, the outermost irregular in 

 shape. The formula is about 60.0.60 x 40. The genital organs 

 are veiy strong and muscular, the male branch set with numerous 

 yellow hooks of the shape usual in the genus : the female branch 

 with stiong folds and lumps. 



I think this specimen may be referred to PI. formosa, or at 

 least that there is not sufficient ground for creating a new species. 

 It is certainly not Fl. arrogans (a'uenta), which has scai-let 

 blotches but a pattern foi'med by minute dark lines, not spots. 

 Allowing for the variations so common in this genus, the coloration 

 corresponds fairly well with Alder and Hancock's description, and 

 the grooved tentacles are a i-emaikable point in common. The 

 chief discrepancy is that the branchial pocket is not distinctly 

 lobed or stellate, as in the typical Fl. formosa ; but I have noticed 

 in many species of Flatydoris that though on an avei'age this 

 character may be very well marked, it may be indistinct in some 

 individuals. 

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