PODJRIlXffi. 



625 



cles, adding that "it is very unusual for an articulate animal 



to have only two spiracles, and their position is still more ex- 



traordinary, for they open on the under side of the head, 



immediately below the antennae, ... on the 



inner side of the basis of the mandibles." 



"In the manner of subdivisions the tracheae 



of Smynthurus differ from those of the true in- 



sects, and agree more closely with the Myrio- 



poda and tracheal Arachnida, in the fact that 



they do not often give off branches nor form 



tufts, but generally divide dichotomously, and 



run considerable distances without a separa- 



tion." (Mr. Lubbock, whom we have just 



quoted, states that Papirius has no tracheae.) 



In Smynthurus the ovaries consist, according 



to Lubbock, of a single egg-tube. On the un- 



derside of the abdomen is a sucking tube, slen- rig. 619. 



der and forked in Smynthurus, but 

 short in Podura, etc., by which the 

 .animal adheres to smooth surfaces. 

 In the genus Podura the body is 

 long, with four-jointed antennae, and 

 the flexible spring-tail is short, while 

 in Desoria, which is found in the 

 Alps, the tail is long. The genus 

 Degeeria is known by the ovate body, 

 and basal half of the spring equal- 

 ling the fork in 

 length. A species 

 rig. 0-20. (Fig. 619) closely 



resembling the European D. nivalis Nicolet, 



we have found in summer resting on the 



leaves of the Clematis. The Lepidocyrtus al- 



binos Nic. (Fig. 620) is a minute pearly white 



species found in Europe ; its scales (Fig. 



621) are thin and with distinct markings. 

 Smynthurus is short, differing greatly in 



form from Podura, and bears a striking resemblance to the 



larva of Coniopteryx. The body is short, nearly spherical, and 

 40 



621 - 



