MALACOSTRACA c<;i 



a frontal spine (rostrum) between the con, /,.,,<,/ /,/,> ,nlate eyes. Gill* borne on or near 

 the basal joints of maxillipeds and leg*, >*i in a branchial chamber formed by a 



ilmmward expm\*inn nf the. carapace on either */</. 



No Palaeo/oie ('nisin.-.-.-in N known which di.-play- tyj.i i li.iractere, and 



it is possible the group did not become differentiated until tin- Trias, where tin- tir-t 

 undoubted remains occur. Thi-ir foivninnrrs, hiwr\vr, an- i-vidi-ntly to be sought for 

 amongst the collective forms already cited undi-r th- ,sVA /:.<,//. Although a <i 

 into the sub-orders Mm-rnni and /;/<"// //C.M is not strictly natural, yet it is of certain 

 convenience to the palaeontologist. The go-called Anomwra, whi.-h an- v.-ry rare in 

 the fossil state, are distributed between these two sub-orders. 



Sub-Order A. MACRURA. Latreille. (Lobsters, Shrimps, Prawns.) 



Abdomen strongly developed, as long or longer than the cephalothorax, and never 

 inflexed beneath the latter ; it is provided with four to Jive pairs of abdominal feet, and 

 the swimmerets of the sixth segment form with the telson a strong caudal fin. Tl< 

 pair of maxillipeds are long and slender, and do not completely cover the preceding ones. 



(1) The family Carididae or prawns have a usually compressed body covered 1-y a 

 delicate cuticula ; legs long and slender, some or all of the pairs chelate ; rostrum 

 usually well developed, and 



large antennal scale present. ^ [ ^* p ** < T^"^ 1 "~>-^ 



Undoubted Caridids are rep re- i^r-j^^taifc...-^^ 



sented in the Lithographic 



Slates of Bavaria by the 



following genera : Penaeus, 



Fabr. (Fig. 1384); Acantho- 



cheirus, Oppel; Bylgia, 



Drobna, Dusa, Aeger (Fig. 



1385), Blaculla, Udora, FIG. 1384. 



Hefriga, Elder, Mitnster ; and Penaeus Meyeri, Oppel. Lithographic Slates ; Solenhofen. 1/2- 



Udorella, Oppel. Pseudo- 



crangon, Schliiter, and Oplophorus, Milrie-Edw., occur in the Upper Cretaceous of 



Westphalia. Homelys, v. Meyer, and Palaemon, Fabr., are Tertiary genera, the latter 



also Recent. 



(2) The Eryonidae have a thin, broad, and depressed carapace, with a nu-dian 

 longitudinal keel ; antennal scale small ; four anterior pairs of feet chelate ; caudal tin 

 large. Tetrachela, Reuss, from the Upper Trias of Raibl, is one of the oldest known 

 Decapods. Eryon, Desm. (Fig. 1386), ranges from the Lias to Cretaceous, exquisite 

 examples being found in the Lithographic Slates. Polycheles, Heller, and fVillemoesia, 

 Grote, are recent deep-sea forms. 



(3) In the Palinuridae (Loricata} the body is stout, antennal scale small, and all 



Boston Soc. Nat. Hist., VII.), 1863. Frittmk A., Ueber die Callianassen der iWihini.M-hfii Krei.le 

 (Abhandl. Bohm. Ges. Wiss. [6], I.), 1868. Carter, J., On Orithopsis Bonneyi (Geol. Mag. [1], 

 IX.), 1872. Decapod Crustaceans of the Oxford Clay (Quar. Journ. Geol. Soc., XLIL), 1886. 

 (Ibid. LIV.), 1898. Woodvxtrd, //., Macrurous Crustacea, etc. (il>i,l. XXIX., XXXII.), 1872-76. 

 Tribolet, M., Descriptions des Crustaces du terrain ueocoinien (Bull. Soc. Geol. France I 

 III.), 1874-75. BMner, A., Brachyureu des vicentischen Tertiargebirges (Deuksdir. Aka. 

 Wien., XXXIV., XLVL), 1877-83. WinUer, T. C. t Etudes sur les genres Pemphix, (Jlyphaea, et 

 Araeosternus (Archiv. Musee Tyler [2], I.), 1883. Ort,n<i,ui. .1. A'., Das System der Decap'-.K-n- 

 Krebse (Zool. Jahrb. Syst. Abth., IX.), 1896. On Liuuparus in tlie Upper Cretaceous of Dakota 

 (Amer. Journ. Sci. [4], IV.), 1897. Moericke, IP., Die Crustaceen der Straiuterger Schichteu 

 (Palaeontogr. Suppl., II.), 1897. Ltircnt/iey, K., Ueber die Brachyuren der pal. Sainmlung des 

 Bayerischeii Staates (Tenneszetrajki Fiizetek Budapest, XXI.), 1898. Beitrag zur Decapodenfouna 

 des iingarischen Tertiars (ibid.; also in Math.-naturw. lier. aus rn-rarn XIV.), 1898. 



