107 
‘The markings are very like P. Hedleyi, but the lateral area 
makes a distinct species. 
Habitat. Port Esperance. One ‘median valve. Aes 
32. A—PUSTY. 
, sp. nov. —~ 
Plate xxv., fig, 7. y O FO 
One median valve was taken at Albany and is in perfect “ 
condition. The valve is slightly arched and beaked. The 
posterior part of the dorsal area has 12 bright-brown trans- 
verse riblets divided by pale-green strie, rather crowded 
toward the posterior. These riblets are continued into the 
pleural area in rows of bright shiny pustules, longitudinally 
parallel, and diminishing in number from seven near the dor- 
sal area to one at the insertion plate. The lateral area is 
slightly raised, but very distinct. It has three or four 
radiating rays of the tear-drop pustules. 
Interior, The sinus is gracefully curved, colour rich 
dark-brown, slightly pectinated. The sutural plates are 
small. The rear part is folded over, making a white limy 
sulcus, ending in one slit at the insertion plate. 
Habitat. Albany, Western Australia. One median 
valve. 
Brighton, 
South Australia. 
EXPLANATION OF PLATES. 
Pratr XXIV. 
1a,b,c,d,¢,f—Ischnochiton verconis, sp. nov. 
2a,b,c,d,e,f—Plaxiphora hedleyi sp. nov. 
Prath XXV. 
$a,b,c,d,¢,f—Acanthochites subviridis, n. sp. 
4a,b,c,d,e,f—Tonicia hullianus, sp. nov. 
5a,b,c,d,e,f—Lepidopleurus niger, sp. nov. 
6—Plaxiphora zebra (median valve), sp. nov. 
?7—Plaziphora pustulosa (median valve), sp. nov. 
a—Dorsal view of entire shell. 
b—Anterior valve. 
c—Median valve. 
d—Posterior valve. 
e—Lateral view of posterior valve. 
f—Portion of girdle magnified. 
Sizes of type specimens are marked in each case 
