CHAPTER XV 



SUBFAMILY LECANIINAE 



The Tortoise Scales 



The body of the adult female is variable in form, usually distinctly 

 longer than broad, sometimes almost circular, frequently convex on the 

 dorsum and concave on the venter, helmet-like in shape and outline. 

 The lateral margins are frequently thin and distinct, if so, usually 

 fringed with marginal setae, margin sometimes wanting or obscure. 

 The segmentation is usually obscure and the coriae are frequently want- 

 ing. The caudal end of the body is not inflated and the cephalic and 

 lateral margins are not provided with a keel. The antennae, when 

 present, are normal in form, usually small, and consist of seven or 

 eight segments. The number of segments and their size may be greatly 

 reduced, sometimes wanting. They are articulated to the ventral aspect 

 of the head, usually distant from each lateral margin. The eyes are 

 present. There is a single ocellana located on each lateral margin near 

 the articulation of an antennae. The mouth-parts, rostrum and rostralis, 

 are always present, the rostrum consists of a single segment. The legs 

 are usually present, they are sometimes rudimentary or wanting, when 

 present, they are subequal in length and normal in form. The profe- 

 mora are never enlarged, and the prothoracic legs are never fitted for 

 digging. The trochanto-femoral and tibio-tarsal sutures of all normally 

 formed legs are always distinct. The spiracles of the mesothorax and 

 metathorax are normal in form and size and ventral in position. The 

 mesothoracic spiracles are never located near the anus. The abdominal 

 spiracles are always wanting. The ventral aspect of the thorax is pro- 

 vided with spinae and canellae and usually with stigmatic clefts. The 

 abdomen is about as long as the head and the thorax together. It is fre- 

 quently convex on the dorsal and concave on the ventral aspect, some- 

 times convex on both aspects. The lateral margins are generally sharp- 

 ly denned, sometimes obscure or wanting. The caudal end is broadly 

 rounded or the caudal portion is produced and, whether rounded or 

 produced, is provided with a distinct mesal cleft. All of the segments 

 are exposed or at least no part of the abdomen is retracted to form a 

 marsupium. The abdomen is always provided with an anal cleft, some- 

 times apparently wanting, due to the fusion of the margins of the cleft. 

 The opercula are rarely if ever wanting. The anal ring is always pres- 

 ent, usually retracted into the anal tube, and provided with six, eight, 

 ten, or more anal ring setae. The anal lobes and anal setae are want- 

 ing. The caudal abdominal segment can not be identified. The body 

 is provided with cerores, but the number is frequently not large and is 

 often limited to the canellae and about the vulva. The body is never 



155 



