Mr. Newport on the Class Myiiapoda, Order Chilopoda. 363 



number, alternation, and form of the dorsal plates (Tab. XXXIII. fig. 33.), and 

 the elongations of the angles of the eight posterior ones, together with the 

 excavations on the four posterior pairs of coxae (fig. 34«). These characters 

 are as well-marked in the New Zealand and Tasmanian species as in the 

 American and European. The number of separate ocelli, organs of vision, 

 are also good secondary characters of species, and the great size and single- 

 ness of these mark one distinct genus, Henicops (fig. 27*, Tab. XXXIII., and 

 fig. 3, Tab. XL.). 



. The specific characters are founded chiefly on the number of the ocelli and 

 labial teeth in the adult, and on the colour and markings of the body. The 

 first of these are in general good structural characters, but they are occasion- 

 ally subject to some variation. Thus, a tooth is sometimes deficient (fig. 31.) 

 on one half of the labium, or is supernumerary on the other. When a tooth is 

 absent, the space it should have occupied is not filled up ; and when a super- 

 numerary tooth is developed, the two are in general crowded into a narrow 

 compass. On comparing the two sides of the labium these irregularities are 

 readily detected. The relative size of the species is also of some value, and 

 the colour and markings are good characters in the recent state; but they 

 disappear and become confused in dried specimens. 



Familia 2. Lithobiid^. 



Scuta dorsalial5, subquadrata, inaequalia: angulis elongatis acutis. Coxarum paria poste- 

 riora excavation ibus ovatis. Antennae elongatae setaceae. 



Genus 2. Lithobius, Leach. 

 Antennae multiarticulatae. Caput latum, depressum. Ocelli numerosi. Labium latum, 

 lamelliforme, antice denticulatum, medio sulcatum emarginatum. 



1. Lith. variegatus (Tab. XL. fig. 2.), capite magno quadrato, ocellis utrinque 16, mandibulis 

 magnis prominentibus, labio complanato profunde punctato antice margine dilatato; 

 denticulis 14 validis acutis nigris, corpore depresso brunneo maculis duabus in uno- 

 quoque segmento saturatioribus, pedibus nigro-fasciatis. — Long. lin. 7j v. 8. 



Lith. variegatus, Leach, Zool. Misc. iii. Lithobius, sp, 2. p. 40. Walker, ' Entomologist,' 

 Jan. 1842, p. 238. Leach, Edinb. Encyclop. vii. 409. Id. Trans. Linn. Soc. xi. 382. 

 Gervais, Ann. des Sc. Nat. 1837, P- 49. sp. 3. Lucas, Nat. Hist. Anim, Artie, t. iv. 

 p. 543. Newport, Annals 8f Mag. Nat. Hist. xiii. p. 98. 



Hab. In Wimbledon Common prope Londinum. {v. in Mus. Brit.) 



