PODLTRID^. 



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- Fig. 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 v by the ovate body, 

 and basal half of the spring equal- 

 ling the fork in 

 length. A species 

 (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 



620- 



