Saussure has described a number of our species (Mem. Soc. Geneve 1863–4–9): Walker many others, (Brit. Mus. Catalogue Blattidae 1868): and Tepper has been a constant worker at this group in South Australia for some years; descriptions of most of his species will be found in the Transactions of the Royal Society of S. Australia between 1893–95, and the Zoology of the Horn Expedition 1896. The Genus _Panesthia_ contains 44 described species ranging from India to Australia, of which 7 are peculiar to this country. _Panesthia laevicollis_ is common in forest land, where it is found burrowing in damp rotting logs. It is a wingless black insect, measuring nearly 1½ inches in length, with the thorax narrow and flattened above the head, the latter furnished with comparatively short antennae; the legs short but very spiny; and the dorsal surface of the abdomen covered with irregular punctures. _Cosmozosteria coolgardiensis_ is a very distinctive, wingless, dull yellow species broadly marked with black on the thoracic segments, and finely barred with the same colour on the upper edges of the abdominal segments. It measures about 1¼ inches in length, and ranges from South Australia to the central parts of Western Australia. _Polyzosteria limbata_ is a large dark brown cockroach margined on the outer edge of the dorsal plates with yellow; it is common in the vicinity of Sydney, and may be often noticed in the neighbourhood of Botany resting on stumps and fences; it has the habit, like several other species, of discharging a most offensive liquid when disturbed. _Polyzosteria pubescens_ is an allied but much larger insect, measures up to 2 inches in length and 1½ inch in breadth; it is of a uniform dull brown tint, and is common about Kalgoorlie W.A., and will be probably found to range over a large portion of the interior. _Polyzosteria mitchellii_ is a variegated, dull metallic green cockroach ranging over the same country, but not more than 1½ inches in length. It has the upper surface margined on the edges with yellow, and is mottled on the legs and under-surface. [Illustration: Fig. 5. Fig. 6. =Figs.= =5= and =6=.--Desert Cockroaches. 5. _Polyzosteria mitchellii_ (Angas). The green-banded cockroach. 6. _Polyzosteria pubescens_ (Tepper). The Pubescent cockroach. (“Agricultural Gazette,” N.S.W.)] _Geoscapheus giganteus_ is our giant cockroach, measuring 2½ inches in length and 1½ across the middle of the body. Like the last three it is wingless, with the large prothoracic shield overlapping the head. In colour it is bright reddish brown, crenulated and very rugose in the centre of the dorsal surface. In the same year (1895) that Tepper obtained this fine species, Saussure described another large roach under the name of _Macropanesthia rhinoceros_, forming a new genus for its reception and adding a second species which he named _M. muelleri_. Family 3. White Ants.