PTEROCERA. 125 



Subsection II. Millipes, Klein, 1753. 

 P. SCORPIO, Linn. PI. 9, fig. 6. 



Labrum with a prominent internal transverse white ridge in 

 front of the concavity of the dorsal tubercle; laterally inllectcd, 

 ribbed between the spines, and with a dentated margin ; the 

 spines nodose, and the posterior one auriformly lobed at the left 

 base ; aperture oiange-red, the transverse ridges within the outer 

 lip and on the inner lip whitish, their interstices purple or nearly 

 black. Length, 5-6 inches. 



Indian Ocean, Philippines. 



It is P. nodosa, Swains. 



P. PSEUDOSCORPIO, Lam. PI. 9, fig. 7. 



Labrum with no distinct internal ridge behind, and with the 

 concavity of the tubercle mostly in advance of the columellar 

 fold; moderately inflected, with single dentiform lobes between 

 the angular and median, and median and postsinual digitations ; 

 the latter obsolete^ or not at all nodose, and the posterior 

 without basal lobe. Color as in .preceding species. 



Length, 6-7*5 inches. Zanzibar. Indian Ocean. 



P. MILLEPEDA, Linn. PL 9, fig. 9. 



Digitations separated by secondary ones intercalated at the 

 right margin ; angle armed with four digitations, the uppermost 

 (rarely absent) being an intercalated one ; posterior digita- 

 tion simple ; laterals, especially the primary, much recurved ; 

 wrinkles on the lips moderately developed, interstices not so 

 deeply colored as in the preceding species. Length, 5-6 inches. 

 Indian Ocean, Mauritius, N. Guinea, Philippines. 



P. ELONGATA, Swainson. PI. 9, fig. 10. 



Angle armed with the three normal digitations ; posterior 

 digitation furnished with a lobe at its left base; lateral digita- 

 tions straight ; lips with well-developed wrinkles ; color as in 

 preceding species. Length, 5-6 inches. 



Indian Ocean. 



P. crocea, Sowb., is a synonym. 



P. -VIOLACEA, Swains. PI. 9, fig. 11. 



Angle armed with three digitations; a posterior and an 



