SUBPHYLUM II 



MYRIAPODA 



793 



and Fhryssonotiis Scudder {Lophonohis Menge). A species of Julus (J. telluster 

 Sciidder) occurs in the Green River Eocene of Wyoming, and another in the Miocene 

 freshwater beds of Florissant, Colorado. 



The older fossil forms are referable to the two extinct orders of Scudder, Proto- 

 syngnatha and Archipolyj^oda. The former of these approaches closely to the Recent 

 order Pencillata, and is represented by the Carboniferous genus Palaeocampa Meek 

 and Wortlien. The second of these orders comprises three families, of which the 

 Archidesmidae resembles the Recent Polydesmidae. Archidesmus Peach (Fig. 1529) ; 



Fig. 1529. 



Archidcsmus maenicoU Peacli. Lower Old Red Sand- 

 stone ; Forfar.shire, Scotland. Vl (after Peacli). 



Fio. 1530. 



Euphohcria nrmigera Meek and Worth. Coal 

 Measures ; Mazoii Creek, Illinois, i/j. 



and Kam'pecaris Page, from tlie Old Red Sandstone of Scotland, are examples. The 

 family Euphoberiidae shows some resemblance to the Julidae of the present fauna, 

 Ijut the dorsal scuta are more or less distinctly divided into two portions corresponding 

 with the pairs of legs. < Among Carboniferous genera belonging to this family may 

 be mentioned tlie following : Acantlierpestes and Euphoheria Meek and Worthen 

 (Fig. 1530); Amynilispes and Eileticus Scudder. Acantlierpestes is regarded by 

 Scudder as probably amphibious, and attains the relatively enormous length of 

 20 cm. {A. giganteus Baldwin). Tlie family Archiulidae is represented in the 

 Carboniferous by Trichiulus and Archiulus Scudder, and Xylobius Dawson. One 

 Mesozoic species, Jidopsis cretacea Heer, from the supposed Cretaceous of Greenland, 

 is of doubtful ordinal position, but may belong to the Archipolypoda. 



Class 2. CHILOPODA Latreille. (Centipedes). 



Body more or less flattened dorso-ventrally, composed of <c variable number of 

 segments {from 18 to 176), with a single piair of legs to each segment. One pair of 

 segmented antennae, the joints being at least fourteen in number, one pair of mandibles 

 and tuw pairs of maxillae. First pair of somatic appendages modified as porverful 

 maxillipeds with poison glands emerging on the terminal claw (toxognaths). Last j)air 

 of appendages {those borne by the antepenultimate segment) modified as copulatory organs. 

 Unpaired genital apertiire on the penultimate segment. Eyes variable in number, simple 

 or compoihnd {Scutigera), often wanting. Respiration by means of tracheae with either 

 paired spiracles in the pleural membranes or single spiracles in the median dorsal line. 



Recent Chilopoda are divided into five orders, three of which have Tertiary 

 representatives, especially in amber, and in the freshwater deposits of Aix in Provence. 

 The following true Chilopod genera are known from the Tertiary : Cermatia Rossi ; 

 Scolopendra Linn. ; Lithobius and Geophilus Leach. The older fossil remains cannot be 

 positively referred to any of the five existing orders. By Scudder they were assigned 

 to two extinct families, named by him Gerascutigeridae and Eoscolopendridae. 

 The former of these includes tlie genus Latzelia Scudder, and the latter the genera 

 Palenarthrus and Ilyodes Scudder, all from the Coal Measures of Illinois. 



[The text for the preceding chapters on Embolobranchiata and Myriapoda has been reA'ised 

 by Dr. Alexander Petrunkevitch, of Yale University. — Ebitou.] 



