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Inner skeleton. For the suspension of tlio pharynx two 

 chitinous furcate processes are fastened to the roof of the an- 

 terior portion of the head. Each process has a hook above the 

 pharynx and a membrane at its lower portion, which connects 

 with the other process. (Fig. 12.) Another chitinous process 

 extends hDuo-itudinally along the roof of the thorax, and serves 

 for the insertion of muscles. Similar organs have been ob- 

 served in many other insects, always serving either for the in- 

 sertion of muscles or for the support of delicate organs. 



Alimentary canal. (Fig. 4.) The most anterior muscular 

 portion of the caiial, the pharynx, first bends upward, passes 

 through a chitinous diaphragm formed by the above-mentioned 

 processes, and then reaches nearly down to the base of the 

 head. At this point its lower part is contracted by a sort of 

 sj)hincter pharyngis. The chitinous and membranous continu- 

 ation, the oesophagus, gradually widens its lumen, and ends 

 with a capacious bladder, the ingluvies, or crop. 



The pharynx has two layers, the inner of which consists of 

 quite large glandular cells, cccasionally including small tracheal 

 branches. The glandular cells are densely grouped in the 

 transverse and longitudinal folds. The outer layer consists of 

 a sheath of ring-muscles, which are, along the longitudinal 

 glandular cell-folds, covered with a layer of longitudinal 

 muscular fibres. The fibres of the longitudinal muscles are 

 broader than those of the ring-muscles. In order to convey a 

 better idea of the complicated arrangement of the two layers 

 in the pharynx, Fig. 14 is added : e and d belong to the 

 outer, a, 6, c and/" to the inner layer. 



The structure of tlie membrane of the oesophagus and 

 ingluvies is perfectly homogeneous, the latter taking charge 

 of the maceration of the semi-fluid nourishment and the ex- 

 pulsion of undigested food. The contents of the ingluvies 

 are in all cases a dirty grey emulsion, mixed with a fine, crys- 

 talline, sand-like sediment. As Amblychila lives in clay-holes, 

 probably it swallows, along with its food, a quantity of clay, for 

 the purpose of comminuting and crushing its food, with the 

 assistance of the triturating muscles of the proventriculus, as is 

 the case in many other insects. 



