Some Observations on the Eggs and Newly Hatched Embryos of Solpuga hostilis White (Arachnida).

Summary. Certain features of the first larval stage of the South African Solifuge, Solpuga hostilis White, are described. The newly hatched larva is provided dorsally with a number of long and very stout brownish setae arranged serially in symmetrical pairs on the head, thoracic and abdominal regions of the body; in the larva which has just been released from the egg, they are folded in a characteristic manner, forming a pattern which is the same in all the larvae. The setae are quite different from the long delicate hairs and setae of the adult Solpuga , being very much longer and thicker in proportion to the body length. Before the rupture of the egg capsule, the eggs show a number of dark lines and markings, forming a pattern which is uniform in a series of 61 eggs. This pattern has nothing to do with the covering of the egg itself but is caused by the dark setae showing through the semi‐transparent capsule, some of them lying side by side to form fairly broad bands. The prominent larval setae of Solpuga hostilis are certainly not found in the newly hatched larva of Galeodes (araneoides and caspius ), the only other Solifugae in which this stage of development has been described; such large setae are very unusual in the newly hatched stages of Arachnida and Myriopoda where the delicate and soft‐skinned larva on emerging from the egg is nearly always devoid of hairs, spines or other cuticular out‐growths. The claws of the appendages and the external appearance of the lateral organ are compared with these structures in Galeodes at the same stage of development.