PAI{AC'()R()TOCA AKKRMANI (aVA li|{ Kn), o35 



tlie inner surface of the epitlieliiun a peculiar, thin, con- 

 tinuous layer of substance (/. sc.) was observed. 'J'he layer 

 carried clusters of black granules. The nature of the layer 

 is obscure; it inay be coagulated digested food which was 

 being absorbed by the columnar epithelium. 



A characteristic feature of the mesenteron of Paracoro- 

 toca is the complete absence of ctecal tubes. In Termi- 

 tomimus, as pointed out by Tragardh, the mesenteron gives 

 off a few, very short, thick diverticula which doubtless 

 represent reduced ca^cal glands, but in Paracorotoca there 

 is no sign whatever of such outgrowths. 



Proctodteum: Ileum. — It is short and narrow and runs 

 obliquely forwards to join the expanded dorsally placed colon 

 (PI. XVIII, il.). There is an outer muscular coat (PI. XIX, 

 fig. 61, m.). The ectodermal epithelium consists of cells of 

 very irregular height with large nuclei (ec). No well-defined 

 cuticle was visible. In transverse section some 5-8 prominent 

 longitudinal ridges of epithelium can be seen projecting into 

 the lumen. 



With the material available it was not easy to ascertain 

 with absolute certainty the number of Malpighian tubules, 

 but in three series of sections only a right and left tubule 

 could be seen joining the ileum dorsally at its junction with 

 the narrow end of the mesenteron (PI. XVIII, e. m. t.). The 

 diameter of the portion of the tubules connected with the gut 

 was very small, and less than half that of the convoluted 

 tubules cut through in the abdomen and posterior part of the 

 thorax. Doubtless the proximal portion of the tubule as it 

 approaches the gut is not excretory, but acts simply as a 

 duct, siuce the cells forming it are not large and swollen like 

 those of the convoluted and more distal portion of the tubule. 

 The number of Malpighian tubules given for Staphylinids 

 is 4, and 6 in the larva j while in Paracorotoca I could 

 ■only detect 2 in the imago and 4 in the supposed larva. 



In Termitomimus there appear to be 4 Malpighian tubes, 

 two on the right and two on the left, opening into the dorsal 

 wall of the extreme anterior end of the proctodaeum. The 



