MYRIAPODA. 



545 



ments, and likev/ise allied to the latter by the 

 construction of their jointed locomotive legs ; 

 these, however, instead of being only six in 

 number, as in the true Insects, are, in the 

 Myriapoda, always at least twelve, and fre- 

 quently extremely numerous, being appended 

 to all the segments of the elongated body, 

 whence the names " Centipedes" and " Mille- 

 pedes," by which these creatures are commonly 

 designated. All the members of the class are 

 apterous ; they exhibit externally a succession 

 of cylindrical or compressed rings, each of 

 which sustains one or more, frequently two 

 pairs of jointed feet, all of very similar con- 

 struction, being generally terminated by a 

 single sharp claw. There is no consolidation of 

 the anterior segments into a thorax resembling 

 that of the Insecta, although many celebrated 

 Entomologists are disposed to regard the three 

 anterior rings as the representatives of the tho- 

 racic segments. Upon the head are placed 

 two antenna? or feelers, which, in one large 

 group, are short, stunted, and composed of 

 seven articulations, whilst in others these organs 

 are long and setaceous, presenting a much 

 greater number of distinct joints. Compound 

 or simple eyes, allied in their structure to those 

 of Insects, are generally, but not always, pre- 

 sent. The mouth is formidable, and, in many 

 respects, resembles that of Insects, being fur- 

 nished with strong mandibles, adapted to de- 

 vour either animal or vegetable substances. 

 All the species breathe air by means of lateral 

 stigmata and tracheal tubes, a circumstance 

 whereby they are at once distinguishable from 

 the CRUSTACEA. Their jointed legs remove 

 them from the ANNELIDA, while they differ 

 from the Insecta in many important particulars, 

 but more especially in the progressive growth 

 of their bodies, by the production of new seg- 

 ments, and the development of additional loco- 

 motive limbs, the number of which increases 

 with the age of the animal, while, on the con- 

 trary, in Insects, the segments that existed at 

 birth are found to coalesce into a smaller 

 number, and the prolegs of the larvae become 

 obliterated when the Insect attains its complete 

 hexapod condition. 



All the Myriapoda are terrestrial in their 

 habits, lurking beneath stones or in the crevices 

 of houses. Many of them inhabit decaying 

 timber, or are found beneath the bark of trees, 

 where they devour such vegetable substances 

 as are adapted to their support ; or, in the 

 case of the more highly organized species, 

 wage war against other animals, upon which 

 they feed. 



The classification of the Myriapoda has hi- 

 therto been and still is exceedingly imperfect 

 and unsatisfactory, apparently in consequence 

 of their very wide distribution and the general 

 similarity of their appearance. Our country- 

 man, Dr. Leach, in his zoological miscel- 

 lany, was one of the first who gave a general 

 arrangement of these animals, which was 

 adopted by Latreille ; but he appears only 

 to have examined the European species. In 

 Griffiths' Translation of Cuvier's Animal King- 

 dom, Mr. J. E. Gray, of the British Museum, 



VOL. III. 



gave the figures of some exotic genera; but of 

 these the Editor left the descriptions very im- 

 perfect, and only made slight references to 

 them in the explanations of the plates. Since 

 that time Dr. J. F. Brandt published a mono- 

 graph of the Myriapoda chilognatha* in 

 which he pointed out several new genera and 

 re-named many, previously established by Mr. 

 Gray. More recently M.P. Gervais has pub- 

 lished his studies on Myriapods,f consisting 

 of a revision of the class and a list of the 

 species, but having overlooked the slight notes 

 given of Mr. Gray's genera, has in one or two 

 instances been led into error. Under these 

 circumstances it is, with very great satisfaction, 

 that we are able, by the permission of Mr. 

 Gray, who has kindly placed his manuscript 

 at our disposal, to lay before our readers the 

 following review of the entire class. 



Order I. CHILOGNATHA, Latr. 

 (Julns, Linn.) 



Antennse seven jointed; rings of the body fur- 

 nished with two pairs of legs. 



Fam. 1. JULIDJE. Body cylindrical, smooth, 

 rolling up into a spiral form and composed 

 of many joints. Each segment formed of 

 three imbricated parts, the upper part co- 

 vering the body and sides of the abdomen. 

 Antennse short, thick. Eyes many in a 

 group. 

 Gen. \. JULTJS. (Fig. 304, 1, 2, 3.) 



2d, 3d, 4th, and 5th joint of antenna elon- 

 gated, attenuated ; 2d longest, 5th and 6th 

 longer than the rest. 



Fig. 304. 



Julus. 



* Bull. Soc. Imp. Moscow, 

 t Annales des Sciences Naturelles for 1837. 



2 a 



