THE CANADIAN ENTOMOLOGIST. 135 



inclined to believe that when the life -history is fully worked out they will 

 be found to number five, which, so far as I am aware, appears to be the 

 usual number in Heteroptera, although there are certain exceptions to this 

 rule. Mention is also made of the absence of a distinctive coloration of 

 the nymphs immediately after moults, a fact easily observable in many 

 Hemipterous nymphs. The plate (IV) for this species shows three figures 

 of the egg, the nymph just hatched and the 2nd, 3rd and "penultimate" 

 (4th ?), instars of C. Stollii and the last-mentioned instar of another species. 

 Two figures of the adult are given, one from above and the other from the 

 side, the latter showing the bug in the natural standing position. In regard 

 to the nymph, the explanation of the plate calls fig. 6 "penultimate instar," 

 while the text calls it "final nymph," which latter it certainly is. To avoid 

 confusion, it seems to me the plate should have termed it "last nymphal 

 instar," which would have been perfectly unambiguous. 



Ripartus linearis is treated of with equal succinctness. The bug is 

 vegetarian, and feeds on the seed-pods of various Leguminosce. The 

 cauldron-shaped dark bronzy-brown, sometimes pruinose ova, are de- 

 posited irregularly on the sterns and leaves of the food-plant. One batch 

 of 11 deposited on September 30th was observed, which gave adults on 

 October 23rd following, which is to say, in 23 days, a remarkably short 

 developmental period for Heteroptera, to be explained by the favourable 

 conditions of heat and moisture, since it would appear that the period of 

 abundance of the insect is the wet season. In our Northern latitudes 

 these changes take longer, although it should be noted that certain 

 microveliie are equally rapid in their transformations in the imme- 

 diate vicinity of New York. The changes in nymphal colouration of 

 Riptortus are noted, and also its resemblance in all nymphal instars to 

 ants. In this it is like our common northern Alydus curinus, the black- 

 ish nymphs of which very strongly simulate our large black Camponotus 

 Petmsylvanicus, and are very often taken with it in clover patches in 

 fields. Whether this resemblance is protective or not would be very 

 hard to say, as the authors remark in regard to Riptortus. The number 

 of moults is given as four, with the corresponding number of nymphal 

 instars. It might seem, perhaps, that some moult has passed unnoticed, 

 possibly the first one, because the cast skins are then very diaphanous and 

 fragile. I know positively of only one Heteropteron with only four 

 nymphal instars, and this I have bred a number of times to ascertain be- 

 yond doubt that it was an actual fact, and not a mere error of observation. 



