428 PEECY SLADEN TEUST EXPEDITION. 



of a single species (in which case the name tahulata of 1877 has priority over variegata 

 of 1880), but there are many diflFerences of detai]. The coloration of the dorsal surface 

 is not strikingly similar : PI. tabulata has no lines on the foot ; its oral tentacles are 

 laro'e and grooved, whereas those of PI. variegata are small and digitate. 



A drawing of the living PI. tabulata made in Japan represents it as brownish yellow, 

 the medio-dorsal area being darker than the marginal regions. The margin itself is 

 lighter and there are five irregular whitish spots on various parts of the back. The 

 whole of the dorsal surface, whatever its colour, is thickly spotted with minute dark 

 purplish dots. The branchiae are greyish white ; the rhinophores have yellowish stems 

 and violet-grey perfoliations. The mantle-edge is much undulated and wrinkled. 



15. Platydoris herdmani, Parran. 



Farran, Opisthobranchiate Mollusca in Herdman, Ceylon Pearl Oyster Reports, pp. 337-8. 



Two specimens from Amirante, similar in appearance and size : about 45 mm. long 

 and 30 mm. broad. 



The colour is yellowish brown with mottlings and spots of darker brown, which seem 

 to lie underneath the skin. On the under surface of the mantle are numerous purplish 

 dots. The dorsal surface is softer than is usual in Platydoris, but is minutely granulated. 

 The branchiae are small and six in number. The pocket is completely closed in both 

 specimens, but its natural shape is probably stellate. 



The mouth-parts are on the whole as described by Farran, though the precise sequence 

 of teeth mentioned by him is not always maintained. The formula of the radula is about 

 45 X 70 . . 70. The majority of the teeth are stout, simply hamate, and often with blunt 

 tips, but at the outer end of the rows there occur more or less degraded teeth of three 

 types : (1) hamate teeth bearing a few irregular jags or denticles below the principal 

 hook ; (2) teeth with pectinate hair-like denticles, simUar to those found in Thordisa ; 

 (3) flat plate-like teeth without any cusp or denticles. 



The vas deferens is thick and broad. It is clothed with a hard yellow cuticle on which 

 are set two rows of scales bearing sUghtly bent hooks. The vaginal hooks mentioned by 

 Tarran were not found, but the external appearance of the species is so distinct that 

 there can be no doubt of its identity. 



16. Asteronotus hemprichii, Ehrenberg. 



See Ehrenberg, Symbolse Physicse, Animalia evertebrata, 1831, and Eliot, in Proc. Zool. Soc. 1903, 

 vol. ii. pp. 384-5. 

 One relatively small specimen from Egmont : length 48 mm., breadth 36 mm. The 

 wround-colour is greenish grey composed of a multitude of minute dots. The tubercles 

 are lighter. The consistency and external features are as usual in the genus. On the 

 underside of the mantle is a broad chocolate band extending nearly all rormd the foot 

 and interrupted only at the tail end. It contains several lighter areas. 



Through the courtesy of the authorities of the Copenhagen Museum, I have been able 

 to examine their specimens of A. hemprichii, Ehrenberg, and A. cespitosus (van Hasselt), 



