86 THE CANADIAN ENTOMOLOGIST 



spiracles of Orthezia cataphracta (Shaw) , one of the three species 

 discussed by him, had been noted by List (5) in 1887 in an ex- 

 haustive paper deaUng with the anatomy of this species. How- 

 ever, Newstead does, indeed, appear to have been the first to note 

 their presence in any other species of this genus. 



As far as I am at present able to determine the following list 

 includes at least the genera in which abdominal spiracles have 

 been noted, although it probably does not include all the species, 

 some descriptions not being accessible. In the subfamily Mono- 

 phlebinfe there are recorded the genera Stigmacoccus with one 

 species, Perissopneumon (perhaps not a synonym of Stigmacoccus 

 as it has been regarded) with two species, and one species of Mono- 

 phlebus. In the Margarodinae there are the genera Xylococcus 

 with four species, Steingelia with two, Stomacocciis with one, some 

 of the species of Margarodes, and at least two of Ccelostomidia. 

 In the Dactylopiina? there is but the monotypic genus Crypto- 

 kermes. In the Ortheziinae there are three species of Orthezia. 



. On the face of these records it would appear that the presence 

 of abdominal spiracles has indeed but little significance and their 

 occurrence migbt well be taken as evidence of aberrancy, the more 

 so as most of the species in which they are recorded are curious 

 enough in other respects as well. However, an examination of 

 even the limited number of species available to me for study has 

 shown that these records are extremely misleading. In short, 

 abdominal spiracles are present in several forms in which they 

 have not been noted and are in all probability present in many 

 others. 



The most surprising fact is that they appear to have been 

 overlooked in such a well known species as Icerya purchasi Maskell, 

 as well as in at least two other species of this genus. In /. pur- 

 chasi Maskell two pairs are present, while in /. seychellariim 

 (Westw.) and /. aegyptiaca (Dougl.) there are at least three. The 

 original description of /. jacobsoni Green is not available and I do 

 not know if they have been noted in this species, but in specimens 

 from the Philippine Ids.'(det. Cockerell) there are at least two pairs. 

 In all these species the spiracles are situated toward the posterior 



(5) List, J. H. Orthezia cataphracta Shaw. In Arbeiten a. d. zool. Inst, 

 zu Gratz, 1 : .5 : 201-278 : pi. 1-6. (1887). 



