298 CLASS vnr. 



The phosphoric light which some species diffuse (Scol. dectrica phos- 

 phorea) is to be ascribed to a fluid that passes upon the skin from open- 

 ings similar to those in the Julidce (Waga). Numerous observations are 

 recorded that myriapods of this division, after having caused lingering 

 head-ache, have been sneezed forth by men from the nose (F. TIEDEMANN, 

 Von lebenden Wurmem u. Insekten in den Geruchsorganen des Menschen, 

 Mannheim, 1844, 8vo, s. n 17, to which examples many others may 

 be added). To reject the observations, is certainly more easy than to 

 explain the continued life of these insects in such an unusual situation. 



Scolopendrella GERV. Antennae with twenty joints, moniliform. 

 Ocelli two. Segments of the body sixteen. Mouth not chelate, 

 suctorial. Habit of Geophylus. 



Comp. Ann. des Sc. nat. troisienie Ser. Zool. Tom. n. p. 79, 8vo, PL 5, 

 figs. 15, 16. Is this its place? Are the sucking Scolopendrce to be com- 

 pared with the Siphonizantia chilognatha BRANDT ? 



SECTION II. Hexapoda. 

 Feet six. Thorax separate from the abdomen. 



ORDER II. Thysanura. 



Hexapod, apterous, not undergoing metamorphosis, not para- 

 sitic. (Mouth with mandibles and maxillae. Two groups of simple 

 eyes. Setas or a bifid tail in most at the end of the body). 



Ovadvovpoi from 6v<ravos, a fringe, a tuft, and ovpd t thus named 

 from some species which have jointed threads at the posterior 

 extremity ; in others there is a forked tail which in a state of rest 

 is bent forwards beneath the body, and on extension gives a blow to 

 the ground, which causes the body to spring upwards : hence they 

 may be named spring-tails. In some however the posterior part of 

 the body has only two small conical hairs (Podura Jimetaria L.) or no 

 appendage at all. The body is generally elongate. Some are very 

 Bmall, and even the largest species are scarcely half an inch long. 

 They love moisture, and live on the ground, under stones, in mould 

 or old fallen leaves, under the bark of trees, in dark corners of houses, 

 <fec. They undergo no metamorphosis, but change their skin often. 



The intestinal canal is straight, the stomach wide. In Lepisma 

 there are two, in Smynthwrus, according to Nicolet, three vessels for 

 secreting urine. The external sexual organs are placed at the 

 posterior extremity of the abdomen. In the female of Lepisma a 

 split tube or borer is found which serves for depositing the eggs. 



