The Phalangidea are remarkable among Arachnids in the possession of large protrusible external organs of generation. The ovipositor of the female may be as long as the whole body of the animal, and the intromittent organ of the male is of almost equal length. The pedipalpi take no part in the fertilisation of the female, which is accomplished directly.
The protrusible organs are concealed under the forwardly-projecting anterior segment of the abdomen beneath, the genital orifice being thus in many cases quite near the head region. The internal sexual organs are not very complex. The ovary re-enters upon itself, forming a ring, and from the point of re-entry a tube proceeds towards the centre of the ring, dilating to form an ovisac. It then narrows, turns forward, dilates once more into a second ovisac, from which the oviduct proceeds to the base of the ovipositor. This is a flattened organ, grooved on its upper surface and bifid at its extremity. The testis of the male is a single sac-like gland, from either end of which proceeds a vas deferens, which, after several convolutions, unite into a sperm-sac which opens at the base of the penis.
Partial hermaphroditism is a very frequent phenomenon among the Phalangids, the testis often producing ova as well as spermatozoa.
Though the males fight fiercely at the breeding time, the animals for the most part live peacefully together. Henking[[343]] found that the eggs of Liobunum, which were about half a millimetre in diameter, were laid during October and hatched out in the following April.
Classification.—The Order Phalangidea is divided into three Sub-orders: 1, Cyphophthalmi; 2, Mecostethi; 3, Plagiostethi.
Sub-Order 1. Cyphophthalmi
Phalangids with dorsal and ventral scutum, only the last abdominal segment remaining free. Eyes two or absent. Maxillary lobe on coxae of first pair of legs rudimentary. Sternum long and narrow. Anterior segment of abdomen not projecting ventrally beyond the coxae of the fourth pair. Odoriferous glands open on prominences.
In 1875 Stecker published a description of a remarkable creature which he said he had found in Bohemia, and which he named Gibocellum sudeticum. Among other points it possessed four eyes and four spinning mammillae, and it differed so much from other Cyphophthalmi as to necessitate the foundation of a family, Gibocellidae, for its reception. No one else appears to have seen the animal, or any of Stecker’s preparations of it, and Hansen and Sörensen[[344]] adduce grave reasons for believing that it never existed at all. If this species is to be disallowed, the Cyphophthalmi all fall into a single family.
Fig. [233].—Parasiro corsicus, enlarged. (After Simon.)