390 Di'. Henry Woodivard — Coal-Measure Crustaceans 



of Saarbriick, vehich are probably of Permo-Carboniferous age like the 

 Gaskoble of Bohemia. 



The eyes in Gampsonyx are said to be pedunculated ; the bases of 

 the antennules are three-jointed and have two nearly equally long 

 flagella ; the antennae support a large rounded scale, and they have 

 a three-jointed peduncle and a flagellum. The head is short, and the 

 hinder part has a strongly marked division as seen in Prceanaspides, 

 and may be a distinct eighth segment, but more probably its separa- 

 tion as a distinct segment is a matter of inteii^retation of the 

 fossil. Gampsonyx has a pair of powerful raptorial limbs belonging 

 (Dr. Caiman believes) to the first or second thoracic legs. The other 

 thoracic limbs (though obscure) appear to agree nearly with the 

 Schizopod type in having an exopodite and endopodite present in 

 each (although the drawing is not very clear). Dr. Anton Fritsch has 

 described two forms ^ under the genera Gasocaris and Gampsonychus 

 which may also belong to this group of Palaeozoic Crustacea of late 

 Coal-measure age. 



2. Acanthotelson stimpsoni, Meek & Worthen, 1865 (Pig. 7). — 

 This crustacean was obtained from the Coal-measures of Illinois (Proc. 

 Acad. Nat. Sci., Philadelphia, 1865, p. 41). Two species are described, 

 viz. A. inoiqualis and A. stimpsoni. Packard, who has given a restora- 

 tion of this genus, considers the head to be composed of two segments, 

 the second being separated by an impressed line from the first ; there 

 is not a true articulation between them. (The eyes are unknown.) 

 The antennules have a three-jointed peduncle which carries two 

 flagella-; the antennae have also a three-jointed peduncle and a 

 moderately long flagellum. The seven separate thoracic segments each 

 bears a pair of long, robust, seven-jointed walking-legs, the first and 

 second pairs being the largest, and having their penultimate joints 

 armed with stout spines. No exopodites appear upon the thoracic limbs. 

 Acanthotelson has five pairs of well-developed setose swimming-feet 

 upon the abdominal segments. The uropods of the tail-fan are slender 

 in form and bordered by spines or bristles, and so also is the telson 

 (see figures of this genus and of Palceocaris in Geol. Mag., 1881, p. 533, 



Fig. 7. — Acanthotelson stimpsoni, M. & "W. Coal-measures : Illinois. Copied 

 from Dr. Packard's figure. 



' Dr. Anton Fritsch, " Fauna der Gaskohle und der Kalksteine du Perm formation 

 Bcihmens," Bd. iv (1901), Heft 3. 

 * Packard only represents one flagellum in his figure (see Fig. 7). 



