164 grosse's classification and 



other thoracic somites. The metathorax is of trapezoidal form, 

 and much broader and shorter than the prothorax. The borders 

 of these somites are strongly chitinised. There are no wings or 

 rudiments of wings. The foremost of the three pairs of limbs 

 are the shortest, and they act as foot-jaws, drawing fragments of 

 food to the mouth. In the male Tetrophthalmus they are large, 

 and also serve for holding the female. The tibia of all the limbs 

 of the male have their inferior end extending into a knob with 

 sharp processes like a "morning star." There are only two tarsal 

 joints, the distal one being the longer and bearing two incurved 

 claws, inclosing between them a soft lobe (pulvillus). The bristles 

 on the tibia and the " morning-star " processes of the male serve 

 for holding the female, which indeed often clambers among the 

 feathers of the host. 



Abdo7nen. — The female of Tetrophthalmus has ten abdominal 

 somites, the terminal one soft and rounded. The male has nine, 

 as the last is invaginated so as to serve as a sheath for the penis ; 

 the hind end of the male is pointed and more chitinised, and 

 more darkly coloured than in the female. 



Digestive track. — Two types of crop are found in the Mallo- 

 PHAGA. In PHiLOPTERiDiE the crop is a lateral diverticulum of 

 the oesophagus ; in LiOTHEiDiE it is a club-shaped symmetrical 

 enlargement of the oesophagus. Kramer divides the intestine of 

 Lipeiirus into an oral cavity, an oesophagus, crop, chylus-stomach, 

 and hind-intestine. The oesophagus reaches back to the abdomen, 

 and has a homogeneous chitinous intima. The intima of the crop 

 has spines, and its cells appear to secrete a fluid. The chylus- 

 stomach extends to the entrance of the malpighian tubules. 

 Grosse finds in the oesophagus of Tetrophthalmus, behind the 

 hypopharynx, a chitin bar produced by thickening of the intima, 

 consisting of a groove-like mid-piece, and running forward and 

 backward into two diverging branches. The hind branches have 

 muscles from the occipital border of the cranium. These chitin- 

 ous bars are not haustellate, but support the oral intima, and in 

 their groove are sent along comminuted fragments of feathers, 

 retained by the retrorse spines and denticulations of the dorsal 

 part of the intima. 



Goniodes has two squamous oesophagal pieces, a dorsal and a 



