260 balanid^e. 



violet stripes : radii (in full-grown specimens) with their 

 summits rounded and surf aces finely ribbed parallel to the 

 basis : basis sometimes permeated bj/ imperfect pores. Scutum 

 intern ally with an adductor ridge. 



Jlab. — Bengal, on wood, Mus. Brit.; on a shell, Mus. Stutclibury ; ^Philippine 

 Archipelago (young specimen), Mus. Cuming. According to Spengler, ou the 

 Coromandel and Malabar coasts. 



General Appearance. — Shell depressed, sometimes much depressed : 

 orifice elongated, rhomboidal, but little toothed; surface smooth, but in 

 old specimens sometimes with the walls slightly folded longitudinally. 

 The radii are rather narrow, with their summits oblique; in old specimens 

 their summits are rounded, and their whole surface finely ribbed parallel 

 to the basis. Colour, in old specimens dirty brown, tinged with violet, 

 sometimes in longitudinal bands, and with whiter irregular marks in the 

 upper parts owing to disintegration : in young specimens the walls are 

 regularly banded longitudinally, with violet-brown and dirty white ; the 

 radii being generally of a paler dirty red or violet. Basal diameter of 

 largest specimen *9 of an inch. 



Scuta, externally rather smooth ; internally, articular ridge promi- 

 nent, reflexed, with the lower edge hollowed out so as to be slightly 

 hook-formed : adductor ridge small ; there is a slight pit for the 

 lateral depressor. Tergum, with the spur bluntly pointed, placed at 

 about its own width from the basi-scutal angle ; there is no longi- 

 tudinal furrow, only a slight depression ; carinal margin arched and 

 protuberant : internally, articular ridge extremely prominent, running 

 down in the direction of the middle of the spur : crests for the tergal 

 depressores well developed. 



Parietes, with the pores rather large ; the internal lamina is very 

 strongly ribbed, the ribs being but slightly denticulated at their bases: 

 the parietal pores do not appear to be crossed by transverse septa : 

 sheath closely attached to the walls. The radii have jagged oblique 

 summits forming an angle of about 45° with the horizon ; in old spe- 

 cimens they become more oblique and narrow : and are then very 

 remarkable from their summits being arched and rounded, with a cre- 

 nated ed«-e, and with their whole surface transversely ribbed in hori- 

 zontal lines; this is likewise the* case with the recipient furrow in the 

 opposed compartments : in young specimens the radii are externally 

 quite smooth : the septa ou the sutural edges are bluntly denticulated ; 

 the interspaces being filled up solidly. The alae have their summits 

 oblique, but much less oblique than the summits of the radii ; their 

 sutural edges are very finely crenated. 



Basis thin, either quite solid, that is, not permeated by pores, but only 

 furrowed in lines radiating from the centre, or permeated by pores 

 towards the circumference, the pores being of very small diameter ; — 

 so that we here have an important character variable within the limits 

 of the same species. Base flat, and this holds good, as remarked by 

 Spengler, even when the specimens are attached to cylindrical pieces of 

 wood. 



