ey 
INSECTA. 291 
Sp. Polydesmus complanatus, Julus complanatus L., Duméri, Consid. génér. 
Pl. 57, fig. 2, Dn Gurr, Ins. viit. Pl. 36, fig. 23 ; 8 lines long, 1 line broad ; 
31 pairs of feet. There are many foreign species of this genus ; comp. BRANDT, 
Bulletin scientifique de VAcad. de St. Petersbourg, Tom. v. and 1x ; Receuil 
de Mémoires, &e. pp. 125—141 ; Newport, Ann. of Nat. Hist. x11. pp. 265, 
266 ; GuRvAIS, GuérIN, Magasin de Zool. 1838. Pl. 240, fig. 1; (Poly- 
desmus margaritiferus from Manilla), &e. In the male there are in the 
seventh ring of the body, on the ventral surface, two hook-like organs 
directed forward, and (behind them) only one pair of feet. 
Craspedosoma Leacu. Eyes distinct. (Sub-genera Craspedosoma, 
Chordeuma, Campodes Kocn). 
Strongylosoma Branpt. Body covered with a hard skin, elon- 
gate, round. yes none. 
B. Middle segments of the body composed of three parts, with 
the ring nearly complete at the dorsum and sides, and two middle 
ventral laminz, one situated behind the other, in whose posterior 
margin the feet are inserted. Z'rizonia BRranpt. 
Julus Li, (exclusive of some species). Body elongate, cylindri- 
eal, covered with hard skin, with segments not marginate. Feet 
numerous. 
Sub-genera: Julus, Spirotrephon Branpt, Spirotreptus Br, 
Spirocyclistus Br., Spiropeus Br., Spirobolus Br., Lurygyrus Kocu, 
Nemasoma Kocu, Blanjulus Gurv., (Allajulus Kocu, no eyes), 
Lysiopetalum Branvv. 
Comp. on the internal structure of these animals Treviranus, Vermisch. 
Schrif. 11. 1817, s. 39—47; Savi, Osservazioni per servire alla storia 
di una specie di Julus, Opuscoli scientif., Bologna, 1. 1817, pp. 32I—337. 
(Julus communis Savi, Julus varius Fasr.); Savi Osservaz, sull? Julus 
fetidissimus (Lysiopetalum fotidissimum BRanp?), op. cit. II. 1819, p. 52 ; 
Newport, On the Organs of Reproduction and the Developm. of the Myria- 
poda. Phil. Trans. 1841. Pt. 11. pp. 99—130, (the article Myriapoda by 
Rymer Jonxs in Topp’s Cyclopedia, 11. pp. 551—360, contains a full 
extract from it). 
These Insects (the Myriapods) live principally on vegetable food : 
some also eat dead earth-worms and small molluscs. They diffuse, 
like many other animals of this family, an unpleasant smell which 
in some species is very powerful ; it is caused by an unctuous fluid, 
with acid reaction (Savr), which is secreted in small sacs or vesicles, 
of which there is a pair situated in each ring. TREVIRANUS erro- 
neously supposed these vesicles to be respiratory organs, and their 
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