THE EUROPEAN OliUYIAS. 1U7 



shown by T. /lo/ipri with the genus ('rratoji/ii/lhis is, in our opinion, but 

 a slight one. The two features from which any relationship might 

 be claimed are the presence of a well-developed eye, and the Oth 

 sternite being fused in the centre. The very peculiar head of this 

 species is also reproduced on the plate. In one female specimen, 

 however, there are five genal spines on uuc side. 



So far we have received ten specimens of this very interesting 

 insect, all from the same host, Mus f<i/lvaticus, as under : — 



1 <S , Lyndhurst, December 19th, 1900 (G. Tate) ; 2 ? , Lyndhurst, 

 December 19th, 1900 (G. Tate) ; 1 <? , Whiteparish, SaHsbury, August IBth, 1901 

 (A. Waters); 1 j , Drayton Beauchamp, February 28th, 1903 (F. .T. Cox) ; 1 ?, 

 Drayton Beauchamp, February 28th, 1903 (F. J. Cox) ; 1 cT , Pitstone, ISucks., 

 May 6th, 1903 (H. Broad); 1 ? , Pitstone, Bucks., May 6th, 1903 (H. Broad) ; 1 

 (f , Pitstone, Bucks., May 7th, 1903 (H. Broad) ; 1 ? , Pitstone, Bucks., May 7th, 

 1903 (H. Broad). 



Explanation of Plate IX. 

 Fig. 1. Head of Tiiphloccras poppei, ?. 

 Fig. 2. Clasping organs of T. poppei, s . 



IX. st. = 9th sternite ; u.p. = unpaired process ; m. = manubrium. 

 Fig. 3. Eighth abdominal segment of T.jyoppei, ? . 



YIII. t. = tergite; Yill. st. = sternite. 

 Fig. 4. Seventh abdominal sternite of T. poppei, ? , spread out. 



The European Orgyias: Their Specialisation in Habits and 



Structure {mtli jdates). 



By T. A. CHAPMAN, M.D., F.E.S. 



(^Concluded from p. 171.) 



It is in accordance with what Mr. Burrows tells me of the habits 

 of 0. (lonostii/Dia, to find that the structure of the female fully 

 corresponds with the very definite steps it has taken towards specialisa- 

 tion, beyond that attained by 0. antiijiia. O. rfunontinuw $ , not only 

 does not want to leave her cocoon, as is also the case with O. antiqiia, 

 but, practically, owing to the outer cocoon, cannot do so, nor has she 

 to lay her eggs with the regularity of O. antujita ; we find, accordingly, 

 the first definite step taken in the degeneration of the limbs and 

 especially of the tarsi and of the antenna?. In (). antiqna ? the antennae 

 (pi. vi., fig. 7) are certainly short, but they are essentially fairly well- 

 developed antennae. In O. <ionosti(jnia (pi. vii., fig. 6) they are not 

 only shorter l^y a fifth part, but we find already four or five of the 

 basal joints of the fiagellum soldered together. 



The tibife of (>. ijimostunua (pi. vii., figs. 1, 2, 8) are a good deal 

 longer than those of (K antiqna (pi. vi., figs. 1, 2, '6), why this is so I 

 do not understand, but it makes more obvious the decline in length of 

 the tarsi, which is very considerable, r/:., by one-third. A very 

 noticeable difference between the two species is that, in (K antiqna, the 

 chitin of the whole surface is strong and dark, that of the head and 

 thorax with the legs being quite black, whilst that of (>. <iiniosti<nna is 

 quite pale and weak-looking. In this, O. :ioni)t<tii/)iia agrees with all the 

 remaining species. One cannot avoid associating this difterence with 

 the exposed life of O. antiqna $ , and the sheltered position in the case 

 of <>. yonostitjnia $ , and of the others in which the shelter consists in 

 never leaving the cocoon. The wings in (>. i/onostii/nta (pi. vii., figs. 

 4, 5) ha^e also further degenerated somewhat in size, but still more in 



