244 THE CANADIAN ENTOMOLOGIST. 



although written in the early years of the last century, are to this day of 

 the utmost importance in the study of the Hemiptera. Locy's work'^ 

 follows in the footsteps of his predecessors, and gives nothing new on this 

 point. In the paper by Schibdte on morphology and classification,*^ the 

 subject is carefully treated. This will be referred to later, since his views 

 have been borne out by my dissections. The only other paper on the 

 subject known to me is that by Marshall and Severin, previously cited, 

 and to be referred to later. In regard to the last paper, it may not be 

 out of place here to mention two points, one being the form of the generic 

 name, which is given as " Ranantra " (recte Ranatra), and the other that 

 the figures, which have been drawn with the aid of the camara, as it is 

 sj^ecifically stated, undoubtedly are of Ranatra quadridentata, Stal., and 

 not R./iisca, P. B. 



The substance of Schiodte's remarks on the respiratory system of 

 Nepa is that they have, in common with all other Heteroptera, ten pairs 

 of spiracles, three thoracic and seven abdominal. In this view, conse- 

 quently, the respiratory semi-tubes are the highly specialized appendages 

 (,f the seventh abdominal segment. Attention is called to the three pair 

 of hir^e sieve-like false spiracles of the abdomen, to which further 

 reference will be made, and to the very small, nearly obliterated, true 

 spiracles. 



In accordance with the results of previous investigators, the main 

 trunk tracheae have their origin in the large spiracles situated a short 

 distance above the insertion of the two halves of the air-tube, in the halves 

 themselves. Thence they go up through the bug's body to the head, 

 giving off branches, many capillary, which go in to aerate the organs, and 

 also the nine main branches to the spiracles. 



Agreeing with Schiodte (op. c), I have found ten pairs of spiracles. 

 It is to be noted that some authors consider the siphon or air-tube the 

 lengthened peritreme of the seventh spiracle, a view that would seem to 

 be reasonable. It is also worthy of notice that there apparently is no 

 device for closing this spiracle, which appears merely as a round opening, 

 as if the tubular trachea had been cut off straight across. The sixth pair 

 of spiracles is situated in the lateral pieces of the subdivided sixth 

 abdominal segment. The next three pair are placed in the peritreme of 



lo. "Anatomy a,nd Physiology of the Family Nepidaj," Am. Nat., Vol. 

 XVIII, 1884. 



I I. On some new Fundamental Principles in the Morpholog-y and Classifica- 

 ion of the Rhynchota, Ann. Mag. N. H.? sen 4, Vol. VI, pp. 225-249. 



