Dec, 1903.] Snodgrass : Anatomy or Peranahrus Scahricoi.lis. 183 



Pl.ATK XI. 



Fig. II. Tiptila caritinta, lateral view of end of abdomen. 



Fio. 12. Dicranomyia ventista, ninth sternum and appendage. 



Fig. 13. Tipula acuta, ninth sternum. 



Fig. 14. Dicranomyia venusta, lateral view of end of abdomen. 



Fig. 15. 5i'W//^f/'rf^««f//]^^««i,y, lateral view of end of abdomen. 



Fig. 16. Tipula bicornis, ninth sternum. 



Fig. 17. Livinophila sciophila, lateral view of end of abdomen. 



Fig. 18. Epip/iragina foriipeiiiiis, lateral view of end of abdomen. 



Fig. 19. Tipula streptocera, ninth sternum. 



Flc. 20. Ptyclioptera lenis, lateral view of end of abdomen. 



NOTES ON THE INTERNAL ANATOMY^OF PER- 



ANABRUS SCABRICOLLIS {TIIOAf.). 



By Roi3Ert E. Snodgrass. 



(Plates XII and XIII.) 



Pcraiuibnis scabricollis (Thorn.) is a large, thick-bodied, short- 

 legged locustid inhabiting the central part of the State of Washing- 

 ton. 'I'he writer has already i)repared an account of its interesting 

 life-history to be published as a bulletin of the Washington Experi- 

 ment Station under the name of the " Coulee Cricket." 



The Alimentary Canal (Fig. 13) has the ordinary Anabnis form. 

 The crop is large, extending back to the posterior edge of the thorax. 

 The ventriculus and small intestine form a complete dorsal loop. 

 The numerous, thread-like Malpighian tubules are grouped in six 

 bunches. The gastric caaca {^:;as. c. ) are two wide pouches embrac- 

 ing the posterior end of the crop. 



The Saliva)-}' Glands (Fig. 4) are composed of groups of race- 

 mose glands in the ventral part of the thorax. The scattered groups 

 (.$■. gls.') on each side are connected by ducts which finally form one 

 main tube (^s. d.). Into this opens the duct from the large sac-like 

 reservoir {s. r.) of the same side. The final right and left ducts then 

 unite in a median duct that opens at the base of the hypopharynx. 



The Respiratory System is highly developed and all of the main 

 tracheal are large. The dorsal longitudinal trunks (Fig. 12, d. I. tr.) 

 lie just at the edges of the diaphragm. Each is connected with the 

 spiracle trunks of same side by two transverse tubes (Fig. 12, t. tr.). 

 The anterior one of each pair is larger than the other. 



