suBPHYLUM II MYRIAPODA 791 



head fused with the thorax ; abdomen segmented, apparently broadly joined to the 

 cephalothorax ; between the tergites and sternites one or two rows of pleural 

 Rclerites ; anus with an operculum which represents the tergite of the eleventh 

 segment ; chelicerae not known ; pedijialiDi short, pediform ; legs seven-jointed with 

 movable coxae apparently articulated to a sternum. Anthracomartus Kartsch (Fig. 

 1525); Brachypyge and Eophrynus Woodward (Fig. 1526) ; Alaiocercus and Trigono- 

 tarbus Pocock ; and Kreischeria Geinitz are Carboniferous genera. 



The order Haptopoda is also confined to the Paleozoic. Head fused with the 

 thorax ; abdomen segmented, broadly joined to the cephalothorax ; pedipalpi short, 

 pediform ; pleura soft, without sclerites ; tarsus of the first pair of legs seven-jointed. 

 Flesiosiro Pocock, from the Carboniferous of England, is the solitary known genus. 



The order Phalangiotarbi, like the two preceding orders, is Paleozoic, Head 

 fused with the thorax ; abdomen broadly joined to the cephalothorax, segmented, 

 with soft pleura devoid of sclerites ; 



several anterior tergites very short, with a ^#^ 



thickened posterior edge ; anus with an ^^ 



operculum, representing the tergite of the y/^ 



twelfth segment ; chelicerae not observed ; exZESa^ZTT^M^^^^ 



pedipalpi short, pediform. Phalangiotarbus II--*^^^^K»^v?'^'---^ 



Haase ; Geratarhus Scudder ; and Arclii- ^'^=^^^^^^^^^^^^^^^023^^^ 

 tarbus{ = Geraphnjnus) Scudder (Fig. 1527) ; ^^^^^^^^<^/^\j<^»^i^^^T/^~^^ 

 Opiliotarbus Vocock ; Discotarbus V&iixxnk.^ pr?^^^^^g>-r ^^^.>. 



etc., are Carboniferous. I.; rrr~~7^ j \ "^-^-^^i 



The order Phalangida or Opiliones n W^ZTji Vi 



(Harvest -spiders) has many fossil repre- ^>Jw~-+v x"- 



sentatives, most of which are preserved in ^^5^ ^X ' 



Oligocene amljer. Head fused with the ^5b ''xj^ 



thorax ; abdomen broadly joined with the Fig. 1527. 



cephalothorax, segmented, the anal oper- ArcTiUarhus roUimlatus Scudder (=GeraphrymLS 



..iilniii rM^rec;ATitinCT tbp tertritp nf the tenth co)-ho?ia/n<s Scudder). Coal Measures ; Mazon Creek, 

 cuium rtpiesenting tne lergu-e oi ine lenin jm^^ig^ under surface, i/i (after Petrunkevitch). 



segment. Chelicerae three-jointed, chelate ; 



pedipalpi pediform ; coxae of the first, often also of the second and third pairs of legs 



with maxillary lobes ; one pair of tracheae. Nemastomoicles Thevenin ; Dinopilio 



Fritsch ; and Protopilio Petrunk., all from the Carboniferous, are referred to this 



order. The first-named of these, however {Nemastomoides claveris Thevenin), may 



possiblj^ lielong to the Anthracomarti. 



The order Acarina, Acari, or Rhynchosfomi (Mites, Ticks, etc.) comprises degenerate 



Arachnids in which the abdomen is usually not segmented and is either broadly 



joined to the cephalothorax or completely fused with it. Coxae of pedipalpi fused 



together ; coxae of legs widely separate, without maxillary lobes. Numerous fossil 



representatives are known from Oligocene amber and Tertiary freshwater deposits, 



the majority of species being referable to Recent genera. Through the Opiliones this 



order appears to be connected with the Spiders. 



SuBPHYLUM B. Myriapoda Latreille.^ 



Tracheate Arthropods with distinctly separated head bearing a single pair of 

 antennae, and a soma composed of numerous {at least twelve) fairly similar segments 



1 Literature: Fritsch, A., Faiuia der Gaskolile, vol. iv. Prague, 1899-1901.— Griimell, F., 

 Quateruary Myriapods aud Insects of California. Univ. of Cal. Publ., Dept. Geol., 1908, vol. v.— 

 Koch, G. L., Die Myriapoden. Regensburg, 1847.— /toc/t, C. L., and Berendt, J. C, Die im 

 Bernstein Ijetiudliclien Crustaceen, Myriapoden, Arachniden uud Apteren der Vorwelt. Berlin, 



