58 BULLETIN OF THE NATURAL HISTORY SOCIETY. 



The variety of forms which now begin to be associated 

 together in the Thysanura, give support to Dr. Scudder's sug- 

 gestion that this group may be regarded as one of " equivalent 

 taxonomic value to the larger divisions of winged insects."* As 

 we learn more of the Palaeozoic insects we are likely to find this 

 group one of greater importance than we could suspect it to be 

 from our knowledge of its prominence in the present age of the 

 world. In this connection it is a matter of some significance^ 

 that in the insect fauna of the Little River group, the oldest 

 known up to the present time, the only insects (three in number) 

 whose bodies are known, are wingless, and hvo of them are Thy- 

 sanurans; while the third was a lowly form, loosely articulated, 

 and with body rings very uniform in aspect, described as the 

 larva of a Neuropterous insect, but also possibly a Thysanuran. 



Some time ago the writer met with the description of a strange 

 aquatic insect (or insect larva), having jointed dorsal appen- 

 dages, observed by Miss Adele M. Field at Swatow, in China. 

 (See plate I, fig. 12). It was found in still pools of fresh water, 

 crawling slowly on water plants. It appeared to feed on micro- 

 scopic objects (heliozoans, rotifers and infusoria). Exuvite 

 of varying size found in the water they inhabit, show that they 

 moult. The head is flat and has eyes and antenna?, but is very 

 small and almost I'educed to a sucking tube ; the thorax has 

 three segments, bearing paired legs ; the abdomen has nine 

 segments which bear long slender jointed appendages containing 

 tracheie. The abdomen was terminated by two sharp, jointed 

 styles, nearly as long as the body. In its general form this 

 insect resembles Archa^oscolex (plate II, fig. 9), in its microscopic 

 head Geracus (see fig. 3 above), and in the stylets, Podurites 

 (pi. II, fig. 8). It is only in sucli rare and exceptional examples 

 as this Chinese insect that we find modern forms explanatory of 

 these strange creatures with which the Reign of Life on tlie land 

 began. 



* Op. cit. 



