suBCLASS II EUCRUSTACEA— EUCARIDA 759 



rarely also the seconcl, fused with the head. Abdomen shorf, ventrally flexed, the 

 last somite usually distinct. Eyes sessile. Thoracic limhs ivithout exopodites, the 

 basal Segments usually lameUar, carrying gills. Abdominal 

 appendages divided into two sets, the last three pairs directed 

 backwards, sfyliform. 



Although various Paleozoic fossils from the Silurian ^ _, 



^ Fio 1473 



{Necrogammarus Woodward) and later rocks have been Gammarus oeningensis 

 referred to this order, it is only in the Tertiary that Heer. Miocpiie ; Oenin- 

 undoubted Amphipods appear. Some of these, from the " ' ' ^' 

 Miocene, are referred to the Recent genus Gammarus Fabricius (Fig. 1473), 

 from which Palaeogammarus Zaddach, foiind in Baltic amber, is doubtfully 

 distinct. 



Division C. EUCARIDA Oalman. 



Carapace coalesced dorsally vnth all the thoracic somites. Eyes pediinculate, 

 No oostegites. 



Order 1. EUPHAUSIACEA Boas.i 



Caridoid forms in which none of the thoracic appendages are specialised as 

 maxillipeds and the gills are in a Single series attached to the bases of the thoracic 

 limbs. 



Anthracophausia from the Calciferoiis Sandstone of Scotland is described 

 by Peach as belonging to this group, but the points of resemblance are very 

 slight. 



Order 2. DBCAPODA Latreille.^ 



The caridoid fades may be retained or may be very greatly modified. The first 

 three pairs of thoracic limbs are specialised as maxillipeds and one or more of the 



G. 0., An account of the Crustacea of Norway, vol. i,, Amphipoda, Christiana, 1890-95. — Stebbing, 

 T. R. R., Report on the Amphipoda, Scient. Resalts Challenger Exped., Zool., 1888, vol. xxix. 

 — Idem, Gammaridea, in Das Tierreich, 1906, vol. xxi. — Zaddach, (7., Ein Aniphipod im Bernstein. 

 Schriften physik. -Ökonom. Ges. Königsberg, 1864, vol. v, 



^ For literature references see under the head of Mysidacea. 



'^ Literature : A. On Recent Forms. — Älcock, A., Materials for a carcinological fauna of India, 

 nos. 1-6. Journ. Asiatic Soc. Bengal, 1895-1900, vols. Ixiv., Ixv., Ixvii. -Ixix. — Idem, Catalogues 

 of Calcutta Museum, 1899-1910. — Bäte, C. S. Report on the Crustacea Macrura. Scient. Results 

 Challenger Exped., Zool., 1888, vol. xxiv. — Boas, J. E. V., Studier over Decapodernes Slaegtskabs- 

 forhold. Dansk. Vidensk. Selsk. Skr., 1880, ser. 6, vol. i. — Borradaüe, L. A., Classification of 

 Decapod Crustaceans. Ann. Mag..Nat. Hist,, 1907, ser. 7, vol. xix. — Bouvier, E. L., Sur l'origine 

 homarienne des Grabes. Bull. Soc. I'hiloniath., Paris, 1896, ser. 8, vol. viii. — Faxon, W., Revision 

 of the Astacidae. Mem. Mus. Comp. Zool., Cambridge, 188.5, vol. x. — Idem, Stalk-eyed Crustacea. 

 Albatross Reports, xv. Op. dt., 1895, vol. xviii, — Henderson, J. R., Report on the Anomura. 

 Scient. Results Challenger Exped., Zool., 1888, vol. xxvii. — Herrick, F. H., The American Lobster. 

 Bull. U.S. Fish Comm., 1895, and Bull. Bureau Fisheries, 1911, vol. xxix.—Huxley, T. IL, On the 

 Classification and Distribution of the Craytishes. Proc. Zool. Soc, London, 1878. — Ortmann, 

 A. E., Die Decapoden-Krebse des Strassburger Museums. Zool. Jahrb. Abth. Syst., 1890-94, 

 vols. v.-vii. — Idem, Das System der Decapoden-Krebse. Op. cü., 1896, vol. xi. — Miers, E. J., 

 Report 011 the Brachyura. Sei. Results Challenger Exped., 1886, vol. xvii. 



B. On Fossil Forms. — Bell, T., Monograph of the fossil Malacostracous Crustacea of Great 

 Britain. Paleontogr. Soc, 1857-62. — Bittner, A., Brachyuren des vicentischen Tertiärgebirges. 

 Denkschr. Akad. Wiss., Wien, 1877-83, vols. xxxiv., xlvi. — Carter, J., On Orithopsis honneyi. 

 Geol. Mag., 1872, dec 1, vol. ix. — Idem, Contribution to the palaeontology of the Decapod Crustacea 

 of England. Quart. Journ. Geol. Soc, 1898, vol. liv. — Cushman, J. A., Fossil Crabs of the Gay 

 Head Miocene. Amer. Nat., 1905, vol. xxxix. — Etallon, A., Description des crustaces fossiles. 



