406 PALEONTOLOGY OF ILLINOIS. 



segments, 0.35 inch; do. of the first six abdominal segments, 

 about 0.31 inch. Length of telson, about 0.14 inch; do. of 

 stylets, near 0.13 inch. Length of lower or outer antennas, 

 not less than 0.38 inch (probably more), of which the pedun- 

 cle forms 0.15 inch; do. of inner, 0.40 inch. Breadth of thorax, 

 0.13 inch. 



Locality and 'position : Same as preceding. 



DEGAPODA. 



MACRURA. 

 ? Genus ANTHRAPAL^EMON, Salter. 



Anthrapalxmon, Salter, 1861. Quart. Jour, of Geol. Soc. of London, svii, p. 529. 



"Carapace scarcely so broad as long, (except when crushed 

 flat), simple, flatter than semicylindrical, the sides a little 

 arched outwards. A strong central ridge in front, projecting as 

 a thick (serrate ?) spine is separated by a concave space, or 

 slight furrow, from a posterior central ridge, which only occu- 

 pies (in the type species, Grossarii) a small portion of the 

 length. Front margin serrated. The outer antennae have 

 wide, square, basal joints, apparently without any advantage;* 

 the second and third joints not much oblique; the rest about 

 as broad as long. Abdomen as broad as long, of six joints 

 (besides the telson), broad and very short; the pleurae, except 

 the second, pointed. Telson very broad ; appendages to the 

 penultimate joint, double on each side, subtrigonal, broad." — 

 (Salter.) 



The name Anthrapalsemon was proposed from its supposed affinities to the 

 recent genus Palsemon, but Prof. Dana thinks it more nearly related to JSglea 

 and Galathea. The original type of the genus was found in the Coal Measures 

 of Scotland. 



* Is this not a misprint of the word appendage? 



