J 
72 Records of the Indian Museum. (Vor. VIT, 
of Khandesh. They were found in the ground and 
are thought to be of similar origin to the ‘ Ground 
Pearls’ of the West Indies.” ‘These examples are 
very old and decomposed and consist mostly of an 
earthy core slightly overlaid with nacreous matter. 
Average diameter 3 mm. Surface nacreous, whitish, 
opaque, rather furfuraceous (from decay), with 
slight lustre, covered with an intricate network of 
fine cracks: inner surface more distinctly lustrous. 
A few examples with traces of one or two large 
overlapping scales (fig. 12): others smooth (fig. 13). 
The loss of colour is evidently due to exposure and 
decay, and the opacity to the presence of air 
between the laminae. 
(e) Pill-box, containing 15 cysts (and some small seeds and 
shells of small molluscs). 
Label:—4146/16. ‘‘ Surface of flood-water, edge of the 
River Hoogley, at Tribeni (near Calcutta), 31-vii- 
T909.”’ Size varying from1to5mm. There area 
few only of the smaller size, the greater number 
ranging from 2 to 2°5 mm. Colour of average 
examples pale yellow to bright golden yellow, irides- 
cent. Form and character of overlapping scales 
similar to the specimens described under (0). 
A single large example of exceptional form (fig. 14). 
Size 5 mm.: colour dull castaneous, without lustre: 
of very irregular form, nodular, overlapping scales 
almost completely obscured. This example may be 
of compound origin, and is possibly of a distinct 
species. 
Any attempt to differentiate the species by the form, size, 
colour or structure of the nymphal cysts is unsatisfactory. All 
these characters are inconstant and vary indefinitely in a single 
parcel. Such differences probably depend very largely upon the 
age and development of the individual. M. mediterraneus appears 
to be exceptional in being devoid of overlapping scales throughout 
its development. In M. rileyi (fig. 18) the scales are larger and 
somewhat looser than in ¢viment (figs. 16, 17) and the West Indian 
forms. The Indian examples that I have seen are, on the average, 
considerably smaller than those from the African and American 
regions; but it would be possible to match individuals from India 
with particular examples of formicarum, triment or rileyr, in size, 
colour and structure. 
The characters of the adult females, where known, are more 
reliable. There are slight differences in the pelage and other 
dermal characters, and in the size and proportions of the limbs. 
The enlarged front legs, in particular, afford useful characters. 
Thus, in capensts (fig. 21), the tibio-tarsus and claw are propor- 
tionately shorter and more robust than in tvzmenz (fig. 22). In the 
