G. 8. Graiiam-Smith 
517 
to flies than in others, Stainton for example noticing unusual numbers 
in 1865, and Hill stating that they were very commonly found on flies 
near Eton in 1905. According to the writer’s observations flies bearing 
pseudo-scorpions were common in 1915. 
“As regards the kinds of pseudo-scorpions in which the habits 
above noted obtain, it must be remembered that with animals of the 
present kind names, in the hands of writers other than specialists, 
have not the value they usually possess in more familiar departments 
of Zoology. Chelifer cancroides , for instance, derived from the Linnean 
Acarus or Phalangium cancroides, was long a stock name for pseudo¬ 
scorpions of any kind; and its use, more especially by earlier writers, 
rarely implies any attempt at specific discrimination....The German 
arachnologist L. Koch states his experience that the species found 
attached to flies is always Cherries Reussii C. Koch = Chernes nodosus.... 
Stecker (1875), referring to this remark, states that Chernes cimicoides, 
not Chernes nodosus, occurred to him under these conditions. All the 
European pseudo-scorpions found on flies’ legs by Simon and by his 
correspondent Mr Ray, of Troyes, proved to be Chernes nodosus ; and 
Mr Cambridge, in England, who does not mention the finding of any 
other species thus situated, states that all, or nearly all, of the individuals 
Plate XXX. Fig. 1. Photograph of a living specimen of S. calcitrans (nat. size) with 
C. nodosus clinging to the tarsus of the left back leg. Fig. 2. Photograph of a 
living specimen of 0. leucostoma (nat. size) "with C. nodosus clinging to the tibia of 
the left back leg. Fig. 3. Photograph of a living specimen of M. domestica (nat. 
size) with C. nodosus clinging to the tarsus of the right back leg. It will be seen that 
in each of these cases the pseudo-scorpion is attached by one claw only. Figs. 4 
and 5. Photographs of a living specimen of M. domestica (nat. size) with C. nodosus 
clinging near the base of the right middle leg. In fig. 4 the fly is seen in the act 
of cleaning its left wing between two legs, and in fig. 5 is rubbing its two front legs 
together. Figs. 6 and 7. Photographs of the dorsal and ventral surfaces of C. 
nodosus ( x 15). Fig. 8. Five puparia (nat. size) of C. er-ythrocephala showing the 
circular and vertical splits produced when the flies emerged. Fig. 9. Seven puparia 
(nat. size) from which braconids, A. manducator, have emerged by gnawing irregular 
oval openings. Fig. 10. Seven puparia (nat. size) from which chalcids, M. acasta, 
have emerged by gnawdng minute round holes. In the left-hand specimen the hole is 
near the centre, and in the nest five near the anterior end. The right-hand specimen 
shows two holes. Figs. 11, 12. Photographs of living specimens (nat. size) of 
A. manducator, which emerged in the autumn. Fig. 13. Photographs of three 
pupae (nat. size) opened longitudinally to show numerous living larvae of 
M. acasta within them. Fig. 14. Photograph of three pupae (nat. size) opened 
longitudinally to show a single living larva of A. manducator in each. Figs. 15 and 
16. Enlarged photographs ( x 2-3) of the left-hand and middle specimens shown in 
fig. 13. Most of the numerous small shining larvae are clearly seen, but some 
specimens which moved during the exposure are slightly blurred. 
