139 



Remarks. — This shell is allied to the living forms Plao:ij)hora 

 petholata, Sby , and P. glauca, Q. and G., rather more so to the 

 latter than to the former. It is more strongly concentrically 

 ribbed, more evenly rounded, sinus narrower, sutural laminse 

 twice the length, the anterior margin of tegmentum slightly 

 produced forward in the centre of the sinus, and the inside is 

 white instead of greenish-blue. The microscopic vermiculate 

 wrinkling is quite absent in the specimen under description. 



5. Plaxiphora g-ellibpandi, n. sjj. pi. iv., fig. i. 



One example of posterior valve. 



General Appearance. — Broad, flat, jugum slightly raised, sid& 

 slope nearly straight. Color blackish, with irregular streaks of 

 green. A pale broad wedge-shaped mark on dorsal ridge. 



Mucro. — Post median, slightly raised. 



Dorsal Area. — Slightly raised and ornamented with a broad 

 whitish wedge-shape mark. A shallow curved diagonal rib run& 

 from the mucro forward, keeping near the margin of valve. The 

 whole of the valve is ornamented with the same peculiar sculp- 

 ture that is present in Plaxijihora petholata, Sby., and which 

 Sowerb}'^ in his description describes as a microscopic pattern 

 resembling a dense punctulation, united with a minute zigzag or 

 vermiculate wrinkling. 



Measurement. — Posterior valve, total width 14 mm., total 

 length 8 mm.; width of tegmentum only, 11 mm.; length of 

 tegmentum only, 5 mm. 



Inside. — Articulamentum white, sinus 3 mm. at apex, increas- 

 ing to 6 mm.; sutural laminse produced beyond tegmentum 3 mm. 



The eves are shallow and spongy. The articulamentum of in- 

 sertion plates and sutural laminae is greatly thickened. The two 

 dorsal pits and corresponding lateral grooves are very deep. 



Locality. — Eocene beds, Gellibrand, Victoria. 



Remarks. — This species very closely resembles P. petholata, 

 Sby. The inside pits and lateral grooves are deeper, and the 

 inside color white instead of greenish blue. The shell is also 

 broader, and the anterior margin of tegmentum is slightly pro- 

 duced forward. 



6. Aeanthochites (Notoplax) granulosus, n. sp. Pi. iv., fig. 9. 



Two examples of median valves. 



General Appearance. — Carinated beaked, side slope straight, 

 except lateral area, which is reflex ; color mottled in two shades 

 of green, somewhat bleached. 



Dorsal Area. — This area is clearly defined, being broadly 

 wedge shape, produced forward in a distinct beak, which is 

 slightly bent downwards. A shallow depression separates this 

 area from the pleural. Sculpture consists of about a score of 



