OP ARTS AND SCIENCES. 13 



III. 



A CONTRIBUTION TO OUR KNOWLEDGE OF 

 PALEOZOIC ARACHNIDA. 



By Samuel H. Scudder. 



Communicated June 11th, 1884. 



Until a very recent period discoveries of fossil Arachnida in the 

 older rocks had been exceedingly few, and the first and only at- 

 tempt to show their relations to each other and to living forms was 

 made in a recent paper by Karsch,* occasioned by his description of 

 a new generic type. Yet the first discovery of carboniferous forms 

 dates back to Coixla, who described f a scorpion found by Sternberg 

 at Chomle in Bohemia, a discovery which justly awakened at the time 

 the widest interest. 



Karsch, in his brief attempt to bring into connected order the dis- 

 coveries of the past, has established for the bulk of the species which 

 do not belong to the scorpions the order Anthracomarti, divided into 

 two families, the Architarboidn^ and Eophrynoidie. 



The following is a succinct account of his arrangement : — 



Order 1. ARANE.'E. 



Body composed of two principal masses, of which the front (cepha- 

 lothorax) is unsegmented, and the hinder (abdomen), unsegmented 

 beneath, has at the most a single segmented dorsal plate. 



Fam. LIPHISTIOIDJE Thor. 



Abdomen with segmented dorsum. 

 Protolycosa antJiracophila Roemer (Silesia). 



Order 2. OPILIONES. 



Body forming either a single mass or two segment-complexes, 

 always separated into segments both above and below. 



* Zeitschr. deutsch. geol. Gesellsch., 1882, p. 556. 



t Verliiiiidl Gesellsch. vaterl Mus. BiJhmen, 1835, p. 35. 



