SUBCLASS II 



EUCRUSTACEA— SYNCAKIDA 



•765 



correctly assigned to the Isopoda, however, the origin of the series must 

 have been considerably earlier, 



Division A. SYNCARIDA Packard.^ 



VIII 



Order. ANASPIDACEA Calman. 



Carapace absent. First thoracic somite fused with the headj or defined therefrom 

 hy a groove. Eyes pedunculate or 

 sessile. Thoracic legs typically with 

 exopodites ; no oostegites. , Uropods and 

 telson forming a tail-fan. 



The name Syn- 

 carida was applied 

 hy Packard to a 

 group of Carboni- 

 ferous and Per- 

 mian Crustacea of 

 which the affinities 

 long remained ob- 

 scure. The dis- 



covery, in 



Anaspides tasmaniae Thomson. 



Fig. 1463. 

 Recent ; Tasmania. 



groove ; ii, viii, Second and eighth thoracic somites 

 dominal somites (after Calman). 



Male, 



; 1, 6, 



>/i. c.gr, "Cervical 

 First and sixth ab- 



the 

 fresh waters of 

 Tasmania and 

 Australia, of living forms with similar characters has thrown a new light on 



Ä . B 



Fig. 14Ö4 



l'alueocaris typua Meek and Worthen. Goal Measures ; Illinois. A, Restoration of body, omitting eyes, 4/^. 

 B, Telson and uropods, 6/^ (after Packard). 



the subject, and reinvestigation of some of the fossils has only emphasised 

 their close agreement with the Recent Anaspides (Fig. 1463) and its allies. 

 Of the fossil genera, Palaeocaris Meek and Worthen (Fraeanaspides 



1 Literature : Jordan, H. , and Meyer, H. von, Crustaceen der Steinkohlenformation von 

 Saarbrücken. Palaeontogr. , 1854, vol. iv. — Brocchi, P., Note sur un Crustace, etc. Bnll. See. 

 Geol. France, 1880, ser. 3, vol. viii. — Fackard, A. S., On the Syncarida, etc. Mem. Nat. Acad. 

 Sei. Washington, 1886, vol. iii. — Thomson, G. M., On a fresh water Schizopod from Tasmania. 

 Trans. Linn. Soc. London (2) Zool., vi., 1894. — Calman, W. T., On the Genus Anaspides, etc. 

 Trans. Koy. Soc. Edinburgh, 1896, vol. xxxviii., pt. iv. — On Pleurocaris, etc. Geol. Mag., 

 1911, dec. 5, vol. viii. — Fritsch, A., Fauna der Gaskohle, 1901, vol. iv., Heft 3, Crustacea, etc. 

 — Woodward, H., Some Coal-measure Crustaceans, etc. Geol. Mag., 1908, dec. 5, vol. v. — 

 Sayce, 0. A., On Koonunga cursor, etc. Trans. Linn. Soc. London (2) Zool., xi., 1908. — 

 Smith, G., On the Anaspidacea, living and fossil. Quart. Journ. Microsc. Sei., 1909, vol. liii. 



