106 G. F. MATTHEW ON THE OEGANIC REMAINS OF THE 



For ten years (1881-1890) Dr. Scudder was at work on the Insect Fanna of the Tertiary 

 lake-basin of Florissant and other localities of western North America. His results were 

 published by the IT. S. Geological Survey, and fill a large quarto volume, with 28 plates, 

 representing this extensive series of fossils. 



The remarkable richness of the Florissant fauna may be inferred from Dr. Scudder's 

 statement that in one summer about 10,000 specimens were collected from these beds ; 

 whereas it had taken Ileer thirty years to gather the 5,000 specimens from Œningen, on 

 which he foi;nded his descriptions. Yet from all the material gathered at Lake Florissant, 

 Dr. Scudder has figured only one, broken example of a Myriapod. 



Modern Myriapods are divided into three orders, Chilopods, Diplopods and Pauropods ; 

 the third of which, only known as Recent, is insignificant both in numbers and size. Dr. 

 Scudder was once disposed to claim that these orders, like those of the True Insects, had 

 originated in the Secondary Rocks (Mesozoic), and that all the Palseozoic Myriapods were 

 included in his new orders, Palfeosygnatha and Archipolypoda ; but he has since discovered 

 examples of the Chilopod forms in the Carboniferous beds. It follows that three, if not 

 four, of the orders of the Myriapods existed in the Palseozoic rocks. 



The Chilopods are distinguished from the Diplopods by the possession of only one pair 

 of feet to each joint of the body, whereas the Diplopods have the ventral plate of each joint 

 in two pieces, and carry two pairs of legs to each joint (except a few anterior joints, which 

 have only one pair) ; their feet therefore are twice as numerous as those of the Chilopods 

 (except on the anterior joints). The Chilopods diifer also in having the body flattened 

 from above. Some small species of this order have been found in the plant beds at St. John. 

 Dr. Scudder has made a separate order, Protosygnatha, of that singular larva-like form 

 described by Meek and Worthen under the name Pal«?ocampus. It has only a few joints (12) 

 and is covered with tufted bristles. A Myriapod with the bristles more uniformly difiused 

 and having more numerous joints, occurs at St. John. 



Omitting Protosygnatha and the few Chilopods from view, the bulk of the Palœozoic 

 Myriapods are included in the extensive order Archipolypoda, characterized by a rounded 

 body of many joints, and having the ventral plate of each somite as in Diplopoda divided 

 into two pieces, with a pair of legs attached to each piece. The anterior half of each dorsal 



plate is elevated, ridged transversely to the body, and frequently bears spines or tubercles ; 

 while the posterior portion is flatter and lowei'. The body in the Myriapods of this order is 



elongated, fusiform, largest in the middle, or towards the anterior end, and is composed of 



many segments. 



A peculiar family, Archidesinida; referred by Scudder to this order, has been found in 



the Devonian rocks of Scotland ; in this family the halves of the dorsal plate of the several 

 joints are scarcely cons<didated ; but the anterior half is more important, both by its size and 



l)y the expanded lateral lamellie that (inianiciit it. Tlicsc curious Myriapoils are timiid in 



tlic Old red sandstone of Forfarshire. 



The most important family of the Paheozoic Myriapods is the Enphnhcriila; distinguished 



li-oni the last by the more or less complete soldering of the two portions of the dorsal plate ; 



in this the elevated anterior portion is ornamented with large, often forked spines, or with 



tubercles. The Euphoberidœ are the typical forms of the order Archipolypoda, and some 



are of great size. According to Dr. Scudder, some species were amphibious, being provided 



Avith organs, apparently of the nature of gills, beside the ordinary spiracles, and with lamel- 



