184 DR. A. D. IMMS ON 



beneath the cuticle. It has undergone division into two unequal plates, which are seen 

 in process of development (PL 37. fig. 4). Unlike tlie adult male, the nymph possesses 

 ten abdominal sterna. The 1st sternum is much reduced and soldered to the posterior 

 margin of the metathorax. The remaining sterna differ but little from their condition 

 in the adult, excepting those of the two terminal segments (PI. 37. fig. 6). The 9th 

 sternum is still unmodified, and exhibits no traces of asymmetry. The 10th sternite 

 resembles that of the adult female in heing longitudinally divided into two similar 

 shields (st. 10 in fig. 6). The 9th and the right plate of the 10th sterna subsequently 

 become fused to form the large asymmetrical subgenital plate. In relation "with the 

 base of each cercus are two basal plates (p.p. in PI. 37. fig. 6). 



The mandibles differ from those of the adult male in being relatively stouter and more 

 massive, and resemble closely those of the female. 



11. The Female Nymph. 



A nymphal instar in the female can scarcely be said to exist. It is indistinguishable 

 from the larva except in point of size and in the development of the genital aperture. 

 It, furthermore, only differs externally from the adult in being paler in colour (light 

 pruinose or chestnitt-brown) and with the cuticle less chitinised. The largest female 

 nymph measured 1925 mm. long, and had 23 joints to the antennae. 



12. Observations on the Biology of the Species. 



The nests of Embia major were only met with in a restricted area between the village 

 or " basti " of Bhowali and the Sat Tal lakes, in the Naini Tal district of the Kumaon 

 Himalaya. Sat Tal is one of a series of five lakes or " tals " found in this district 

 of Kumaon. According to Theobald they owe their origin to obstructions in the local 

 drainage caused by the debris of old moraines when the glaciers receded at the close of 

 the glacial epoch *. The name Sat Tal means " seven lakes," and in former times 

 seven small lakes actually existed. At the present day, however, only two lakes of 

 appreciable size remain, and the larger of these, Sat Tal proper, is situated at an altitude 

 of 4500 feet above sea-level. The nests of the Embia were found at elevations varying 

 between about 4900 and 5100 feet, and If miles distant from the lake. They occurred 

 under loose flat pieces of stone which lie scattered in the form of debris over a hill-side 

 and open valley (text-fig. 5). Such situations are neither very dry nor very moist. The 

 area within whicli Embia was found is very thiuly forested, and the trees consist for the 

 most part of " chir " pine (Pinus longifolia), Himalayan oak (Quercus incana), and 

 Rhododendron arboreum. Plat stones were selected almost without exception as the sites 

 for the nests. Between the lower surface of such stones and the ground, the Embiids 

 weave the silken tunnels which form their nests. The shape of the nests depends upon 

 the form, length, and number of these tunnels. In eight nests the ground beneath 

 such stones was found to be occupied both by the Embia and an undetermined species 

 of Termite. The tunnels of the Termite were alongside and in close contact with those 

 * Theobald, "The Kumaon Lakes." Rec. Geol. Survey India, xiii. 1880, p. 161. 



