1867.] 31 
of their location. It may be added in favour of this view, that where 
one only of the sexes is fully winged, it is the male, which happens in 
analogous instances among the Lepidoptera and Coleoptera. Indeed, the 
idea of a species includes that of an elasticity or power of variation within 
limits, such as this now before us, or in size, colour, or marking. 
The following enumeration shows the indigenous species in which 
the imperfect development has occurred, the parts of the elytra affected, 
the degree of the imperfection, and the approximate proportion of the 
individuals of a species in which the peculiarity has been noticed. 
1. — Elytra and wings entirely wanting. 
Hydrometra Najas, Be G "^ ^ 
Velia currens, Fah )^ H yduometkina j, almost the only form. 
Microvelia pygmsea, L. Duf. J 
Limnobates stagnorum, Lin Limnobatina. 
J 
2 . — Clavus wan ting, or not distinguishable. Goriiim rudimen tary or sJiortened 
Membrane absent or merely rudimentary. Wings wanting. 
Myi-mus mu-iformis, J'all the usual form Coreina. 
Pithanus Markeli, ff. Schf. almost the only form. "^ 
Sphyrops ambulans, i^aW., ? ") 
Byrsoptera caricia, ^aZL, $ 3 
Globiceps dispar, Bo/i,., $ the usual form. , 
„ „ . -r ■ r^ C Capsina. 
Syatellonotus triguttatus, I/in., ¥ •• "^ 
Agalliastes saltitans, J^al? 
„ Wilkinsoni, Boug. ^ Scott }■ the only form. 
Orthocephalus mutabilis, Fall., ? I r 
,, saltitans, Jfa^, '^ ... J 
Myrmedobia coleoptrata, Fall., ? "^ ] 
Zygonotuspselaphiformis, PFesiw. ? ^ the only form. | 
„ elegantulus, Biirens., ? J 
Temnostethus pusillus, H. Schf. 
Piezostethus rufipennis, 
Acanthia lectulai-ia, Lin the only form. I 
Metastemma guttula, Fai ") ") 
Nabis limbatus, 2)a?iZ& j the only form. J Eeduvina. 
3. — Clavus 7nostly narrowed. Corium abbreviated, truncate or rounded 
posteriorly . Membrane wanting or merely rudimentary. Wings 
wanting or rudimentary . 
Pyrrhocoris apterus, Lin the only British form ...Coecigenina. 
Ehyparochromus antennatus, 8cMll...t'he usual form. -, 
Hypnophilus micropterus, CiM-i almost the only form, i 
„ hemipterus, Sf/uW the only form. L Lyg^una. 
Acompus ruiipes, Wolff 1 
Ischnodemua sabuleti, Fall j *^® ""^"^^^ ^°^'^^- J 
13, H. Schf. ... 1 
^ _ , f the usual form, 
us, L. Buf. ... ) 
Anthocoeina. 
