ENTOMOLOGY-MYRIAPODA.

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differ from them entirely in their mode of growth and development. TheMyriapoda acquire a periodical addition of segments and legs, with theirseparate ganglia, nerves, and other structures. This addition of new partsat each change of tegument takes place in all the Myriapoda up to a certainperiod of their growth, which period varies in different genera. But thisaddition of parts never occurs in insects, even in the lowest forms of theclass, or even in their earliest stages, after leaving the ovum.”

The author enters yet more fully into these considerations, and if in cer-tain points he has gone too far, as in denying the after formation of legsin insects, which is a necessary condition where the larvee are destituteof them, still the comparison on the whole is convincing. He then goes onto controvert the high authority of Brandt, regarding, as Leach and Latreillehave done, the Myriapoda as a distinct class. It is a step gained in thisinquiry that the author attaches importance to the mode of development;and if he had not at the outset dismissed from his mind the comparisonbetween Myriapoda and Crustacea (among which he probably had in viewthe Crayfish alone, as is often the case), it is likely he would have clearlyperceived their close agreement. In the arrangement of the MyriapodaNewport has in general followed Brandt, except that he has come nearer tonature by breaking up the sub-order Siphonizantia of the latter. A. numberof new genera are proposed by him, particularly among the Scolopendrae,which has made the more precise determination of the older genera neces-sary. To render tills summary complete I insert the Synopsis generum, ashe has given it.

[As this has been given also in the Annals of Natural History (xiv, 50-53),it seems unnecessary to transcribe it here.]

In continuation, the external structure of the Myriapoda is described.Newport regards each separate segment as consisting of two subordinatesegments, of which one only (the hinder) comes to perfection in the Chilo-poda, while in the Chilognatha the ventral plates at least of both aredeveloped in an equal degree, each bearing a pair of legs. The completelyerroneous explanation of the parts of the head, applied to the Chilopoda , issurprising in so judicious and penetrating an anatomist. He considers thelarge pair of pincers as the mandibles, which obliges him to treat the seg-ment on which they are seated as a portion of the head, “ basilar segment,”while the true head is denominated “ cephalic segment.” As a natural con-sequence, the structure of the mouth is misunderstood. The mandibles aredesignated maxillee, the maxill® maxillary palpi, the third pair of jaws tongue,the first pair of legs labial palpi. The parts which he takes for the man-dibles are the first pair of legs, his basilar segment is the mesothorax. (SeeErichson’s Entomographien.) The side view of the fore part of a very youngGeophilus, which Newport has given in fig. 3, is particularly instructive.