756 



ARTHROPODA 



PHYLUM VII 



Woodward) (Fig. 1464), from the Coal Measures of England and North 

 America, is now the most completely known. It resembles Anaspides in 

 general form, in the segmentation of the body, the pedunculated eyes, the 

 characters of antennules, antennae, and even of the minute mouth-parts^ the 

 exopodites of the thoracic legs, and the form of the tail-fan. The only 

 important difference between the two, apart from the delicate lamellar gills 

 which could hardly be looked for in a fossil, is the presence in I'alaeocaris of 

 a wedge-shaped first thoracic somite, which, in Anaspides, is fused with the 

 head. 



Uronedes Bronn (Gampsonyx Jordan and v. Meyer) (Fig. 1465), from the 

 Lower Permian of Saarbriicken, resembles Falaeocaris, 

 but has one of the anterior pairs of legs enlarged and 

 armed with spines. Acanthotelson 

 Meek and Worthen, and Pleurocaris 

 Caiman, from the Coal Measures of 

 Illinois and of England respectively, 

 have the first thoracic somite fused 

 with the head and may perhaps have 

 no thoracic exopodites. These exo- 

 podites are also stated to be absent in 

 Gasocaris Fritsch, from the Permian 

 Gaskohle of Bohemia. Falaeorchestia 

 Zittel (Fig. 1466) and Nedotelson 

 Fio. 1460 PaiMorcMstm paraiieia Brocchi, are less Completely known, 



Uronedes fimhrtatus (Fntsch). Coal Meas- i i p n • ^ ^ • ■ 



(Jordan). Rothlie- iires ; Lisek, near Beiann, and are doubtfully included in this 



gendes ; Lebach, Saxony. Bohemia. i/j (after 



i/j. Fritsch). group. 



Fig. 1466. 



Division B. PERACARIDA Caiman. 



Carapace, when present, leaving at least four of the thoracic somites distinct ; 

 first thoracic somite always fused with the head. Eyes pedxincidate or sessile. 

 Oostegites attached to some or all of the thoracic limbs in the female, forming a brood- 

 pouch. 



Of the orders included in this division, two, the Cumacea and Tanaidacea, 

 are unrepresented in the fossil state. 



Order 1. MYSIDACEA Boas.^ 



The caridoid fades is retained. The carapace extends over the greater p)(^'>'t of 

 the thoracic region, hut does not coalesce dorsally with more than three of the thoracic 

 somites. 



Among the caridoid forms known from Carboniferous rocks, Pygocephalus 

 Huxley, from the English Coal Measures, has recently been shown by 



^ Literature: Sars, G. 0., Report on the Schizopoda. Scient. Results Challenger Exped., 

 Zool., xiii., 1885. — Salter, J. ]V., Higlier Crustacea from British Coal Measures. Quart. Journ. 

 Geol. See, 1861, vol. xvii. — Etheridge, R., Occurrence of Anthrapalaemon in Carboniferous of 

 Scotland. Ibid., 1877, vol. xxxiii. — Ortmann, A. E., The Systematic position of Crangopsis, etc. 

 Anier. Journ. Sci., 1897, ser. 4, vol. iv. — Woodioard, //., On i\\& gewns Pygocephabts, etc. Geol. 

 Mag., 1907, ilec. 5, vol. iv. — Peach, B. N., Monograph on Higher Crustacea of Carboniferous Rocks 

 of Scotland. Mem. Geol. Surv. Great Britain, 1908. 



