SUPER-ORDER CUCULLATA. Distinguished from the rest of the Arachnida by the presence of a large plate jointed to the front of the carapace and folding like a hood over the mandibles, by the construction of the first and second abdominal segments and their concealment between the third segment and the cephalothorax which can be locked together by means of the basal segment by the last pair of legs; and by the telescoping of the reduced last three segments of the abdomen within the enlarged sixth segments.
Order Ricinulei (Podogona). Mandibles chelate, two jointed, palpi small, chelate, basally united to form a suboral trough and in contact with the corresponding segments of the second legs, which like those of the succeeding pairs meet in the middle line practically obliterating sterna. A single pair of tufted tracheae above the base of the third pair of legs. Intromittent organ of male on the tarsus of these limbs.
Family Cryptostemmidae (Cryptostemmus, Cryptocellus). These remarkable arachnids are found in tropical Africa and America. Related genera (Paliacliera, etc.) occur in the Coal Measures.
This order was classified by Hansen and Sorensen with the or ders above referred to the Caulogastra, the group being compre hensively called the Micrura.