SUBFAMILY LECANIINAE 159 



frequently present, but instead of being arranged to form the 

 corners of a four sided figure are frequently placed in a transverse 

 or approximately transverse line. 



The mouth-parts are normal in form and position. The rostrum 

 consists of a single segment. Its distal margin is rounded. There 

 is a prominent crumena connecting with the cavity extending 

 through the rostrum in which the loop of the rostralis is held. 

 The tendons attached to the proximal end of the mandibles and 

 the maxillae are prominent and the tendons attached to the in- 

 funda, the hypopharynx of Berlese and Green, are very large. The 

 ventral aspect of the endoskeleton of the head, the so called cradle 

 of Green, is bounded on the ventral side by a broad band, the 

 clypeus of Green. This latter structure, however, is always located 

 within the lumen of the head and since the clypeus is a sclerite of 

 the external skeleton, can not be considered as homologous with the 

 clypeus. This band has been called the clavus and the so called 

 cradle is derived from the tentorium, consisting in the main of the 

 arms of the metatentoria. 



The legs, when present, are completely developed and all 

 parts are present, although they are frequently so small that their 

 tips project only slightly or not at all beyond the lateral margin 

 of the body. The tip of the tarsus frequently bears a pair of long 

 slender dorsal digitules and the claws a pair of short and stouter 

 ungual digitules. 



The spiracles open on the ventral aspect, each mesothoracic 

 spiracle just laterad of the articulation of a prothoracic leg and 

 each metathoracic spiracle about in line with a mesothoracic 

 spiracle and midway between the mesothoracic and metathoracic 

 legs. The spiracles of this subfamily are frequently figured as 

 distinct trumpet-shaped or hourglass-shaped structures. All of 

 which except the opening, the spiracle, is a cavaera. 



There is extending from each spiracle to the lateral margin 

 of the body in most species a more or less distinct furrow. Each 

 of these furrows is a canella, which bears a varying number of 

 cerores, the spiracerores. They are also known as the grouped 

 orifices of the thoracic spiracles, glandular pores or spinnerets, 

 spinnerets of the spiracles, glands of the spiracles, parastigmatic 

 glands, and parastigmatic pores. They were first named in the 

 Diaspidinae where the canellae and spinae are always wanting. 

 These cerores excrete a powdery wax which serves to keep the 

 canellae open and permit the ingress of air to the spiracles. There 



