194 



externally, trausform to pnp?e close to the remains of the host in the 

 burrow or leaf mine, usually attached at the anal end by the praepupal 

 excrement. I have observed a curious variation in the case of Chryso- 

 cliaris smgularis in the jnine of Lithocolletis hamadryadella on O'akleaYea 

 which I have described in the American Naturalist for January, 1881. 

 In this case the Chalcidid pupa is surrounded by small excremental pil- 

 lars arranged in an ellipse and connecting the roof and floor of the mine 

 (Fig. 18). It can not be stated whether these piUars are formed of 

 regurgitated matter or of anal excrement, although the former hypothe- 

 sis seems the more propable. It is likely that such arrangements as this 

 will be found frequently when the parasites of the leaf-miners are care- 

 fully studied. 



The internal parasites ot externally feeding larvae also transform to 

 outside pupie in a few instances, as with the Eulophine genera Cra- 



totechus and Sympiezus, and 



probably with other genera of 



^ this subfamily. These forms 



]% are common parasites of several 



,>-' 1 arge lepidopterous larvae which 



feed on the leaves of oak and 



sycamore in the United States. 



The host larva affords food for 



a number of the jiarasitic larvae 



and is almost entirely consumed 



by them. When ready to trans- 

 no. 18.—Leafmineofii</»ocoH?*is/tamadr2/ode«iawith form, the parasitic larvae crawl 

 topremovedshowingpupaof Chrysoehanssingtdaris out UpOU the leaf, VOid their CX- 

 and supporting pillars, slightly enlarged (original), ^^emeut, and chaUgC tO Shape- 



less, dark-colored pupae, nearly erect in position, the anal portion of 

 the body being attached to the leaf by means of a small mass of light- 

 colored excremental pellets. They seem preferably to station them- 

 selves in the form of an irregular ellipse about the remains of the host 

 larva, each group consisting of from 15 to 40 individuals. Scudder, 

 in his " Butterflies of New England " (p. 455), gives a happy picture of 

 the appearance of the pupae of an undescribed species parasitic on the 

 larva of Vanessa atalanta, in the following words: 



And still another parasite [a species of Eulophns], the coal-black chrysalides of 

 which one may sometimes find to the number of twenty or more, standing erect on 

 their hinder ends around the corpse they have destroyed, like tombstones in a cem- 

 etery, a most melancholy spectacle on opening a nest to get a young caterpillar. 



In correspondence with me Mr. Scudder has always referred to these 

 as " my tombstone pupae," and the term is an admirably descriptive one. 

 The appearance of these larvae is well illustrated in Fig. 19, which Dr. 

 Riley had prepared several years ago with the intention of publishing 

 it in connection with an account of some observations of his own upon 



