EXPI.ANATION OF PIRATE VII. 

 Figs, i, 2. — l^orms oi Dichelaspis tridens. 

 ,, 3. — Dichelaspis bathynomi (typical form), 

 ,, 4 — D. bathynomi var. perfidiosa. 

 , 5 — 7. — Pœcilasma minutum. Figure 5 represents an old and fig. 6 a young 



individual. 

 ,, 8. — Carina of Pœcilasma kœmpferi subsp. dubia from the Gulf of Manaar. 

 ,, 9, ga. — Heteralepas nicobarica, sp. nov. 

 ,, 10, 10a, lob. — Valves of Oxynaspis célata, subsp. indica — 

 Fig. 10. — -Scutum and tergum (external surface). 

 ,, ID«. — Scutum of another individual (internal surface). 

 ,, 10&. — Carina. 



