I'l. AMPHORA. 



Shell somewhat sculptured. (iinlh- covered with rri-p hair-, not 

 forming bunches at tin- .-mures, nor having pores there. 



P. PETHOLATA Bowerby, 1M. 68, figs. <L'. 68, ''.i 87, 



Shell elliptical or oblong, rather depressed, the dorsal angle 

 rounded but side-slopes rather straight. Surf ace finely corrugated at 

 the nitl'*, nearly smooth in tin mi>l<lle. Color black or blue-black, 

 with pink, creamy or greenish-white angular markings at the sides, 

 and a wide triangle of the same light tint on the ridge of each valve, 

 generally enclosing a dark, ill-defined dorsal stripe. 



The median valves are slightly beaked. Lateral areas hardly 

 raised, defined by a narrow, inconspicuous and slightly cum--! 

 diagonal riblet, the surface finely corrugated in zig-zag or vermic- 

 ulate pattern. Central areas corrugated zigzagly at the sides, in front 

 of the diagonal ril>, th>- corrugation becoming fun. r toward the middle, 

 and giving place to a microscopic pattern resembling a dense punctula- 

 tion united with a minute zigzag or vermiculate wrinkling. Anterior 

 valve having about 9 narrow radiating riblets, the intervals densely 

 and finely zigzag-punctate. Posterior valve depressed, wide and 

 short, the mucro at the posterior edge, slightly acute and a little 

 elevated ; posterior area of the valve very narrow, ill-defined. 



Interior dark blue-green. Sinus deep, uide, angular, its edge light 

 brown and very spongy. Anterior valve having 8 slits, correspond- 

 ing to external riblets, central valves 1 slit ; the teeth acute, some- 

 what thickened at the edges of the slits. Posterior valve having a 

 rather blunt, smooth insertion plate, interrupted by a shallow sinus 

 in the middle behind. Eaves very narrow, spongy. 



Girdle rather wide, black-brown and brown alternately, rather 

 densely clothed with corneous or dark brown bristles, large and 

 small, not in the least arranged in series or issuing from sutural 

 pores. 



Length 40, breadth 27 mill.; divergence 125. 



Length 32, breadth 18 mill. ; divergence 130. 



Length 45, breadth 25 mill. 



Australia (Sowb.) ; Tasmania (Cuming.) 



Chiton petholatiis SOWB., Mag. of Nat. Hist. New Series, iv, p. 

 289 (May, 1840) ; Conchol. Illustr., f. b'4, 65, and var. porphi/ri,'*, 

 f. 59. REEVE, Conch. Icon., f. 74. fctijilm'ijJtnra petholata CPR., 

 MS. Not Plaxiphora petholata ANGAS, P. Z. S. 1865, p. 187 and 



