141 



Lateral Area. — This area is separatfed from the pleural area by 

 a much raised, broad, diagonal rib. This rib occupies fully one- 

 half of the area ; on the other half are two shallow radial ribs. 



Pleural Area. — This area appears to have been sculptured 

 right up to the dorsal ridge, with about 13 sharply chiselled, 

 imbricating longitudinal ribs. The sutures between the ribs are 

 deeply cut, and end as they reach the raised diagonal rib of the 

 lateral area in a very deep pit So deep are these pits that with 

 the naked eye they appear to be perforations through the teg- 

 mentum. 



Dorsal Area. — This area is much worn, but, as before stated, 

 there are indications that the ribbing of the pleural area was 

 continued right over this area. The valve is slightly beaked, 

 which is smooth, no strife being discernible. 



Measurement. — Greatest width between the slopes, 10 mm.; 

 greatest width of slope, 4 mm.; length of slope, 7 mm.; diver- 

 gence, 95°. 



RemarJis. — Under a strong lens<' the whole valve, except the 

 beak, is found to be decussated or ornamented with a network of 

 perforations, this being due to the exceptional development of the 

 megalopores. The sutural laminae are much broken away, but 

 the sinus was probably fairly broad and shallow. The insertion 

 plates are quite missing — they have probably broken awa5^ The 

 most striking feature of this shell is the diagonal row of deep pits 

 in the pleural area, and the much elevated broad diagonal rib of 

 the lateral area. 



Locality. — Table Cape. 



9. Chiton paueipustulosus, n. sp. Pi. iv., fig. 2. 



One medium valve from Table Cape. A well-jDreserved speci- 

 men. 



The Lateral Area is slightly raised, and contains a number of 

 wavy transverse sulca':ions, or growth lines, extending into the 

 pleural area. There are 12 to 14 small pustules on the anterior 

 margin of the lateral area. 



Pleural Area. — The growth lines are very distinct in this area, 

 and extend across the jugum. There are about 12 short longi- 

 tudinal imbricating riblets, those nearest the jugum being the 

 longest, and becoming shorter as they approach the centre of 

 slope, those near the centre being mere elongated lumps. From 

 the centre to the girdle they are absent. 



Length of dorsal area, 6 mm. Sinus wide, increasing from 2 

 to 4 mm. The sutural laminae are 3 mm. wide near the sinus, 

 gradually lessening towards the girdle. The pectination of the 

 teeth is fairly distinct. 



Measurement. — Width, 25 mm.; length of area, 6 mm.; diver- 

 gence, 105°. 



