CARDED | 3/4 
HI—ON THE ANTHRACARIDA, A FAMILY OF CARBONIFEROUS MACRU- 
ROUS DECAPOD CRUSTACEA. 
READ APRIL 21, 1885. 
By A. 8. PACKARD. 
Having been kindly favored by Messrs. R. D. Lacoe and J.C. Carr with the opportunity of 
examining their collections of nodules from Mazon Creek containing Anthrapalamon gracilis Meek 
and Worthen, I have been able to discover some features probably not shown in the specimens 
examined by Messrs. Meek and Worthen. The newly observed characters are the carapace with 
its rostrum, showing that the American species in these respects closely resembles the European 
ones figured by Salter, the founder of the genus. Moreover, our specimens prove the existence of 
five pairs of thoracic legs, while the antennae of both pairs are almost entirely shown. The fact 
that the first pair of thoracic feet were scaicely larger than the succeeding pairs, suggests that 
Anthrapalemon cannot be placed in the Eryonidie, but should form the type of a distinct group of 
family rank, none of the existing Macrura, so far as we are aware, having such small anterior 
legs. Other characteristics which we ahall point out confirm this view. 
The genus Anthrapalemon, a Carboniferous fossil, was first described by J. W. Salter in the 
Quarterly Journal of the Geological Society of London (xvii, 529, 1861), The name given to the 
fossils has, the author remarks, ‘only a general signification, and is not intended to indicate a 
real relation to Palemon.” He also remarks that ‘‘the genus is not to be confounded with any of 
the Liassic or Oolitic ones published by von Meyer, Miinster, &c. . . . It is broader than the 
general form of the Astacidie, or than Glyphea and its Liassic allies, but much narrower than Hryon.” 
Salter’s type-species is Anthrapaleamon grossarti Salter.* With this species the American A. 
gracilis is congeneric. A closely allied English form, A. dubius Prestwich, is referred by Mr. Salter 
to the subgenus Palwocarabus, a name even less fitting than Anthrapalemon. Concerning the 
other form provisionally referred to Antbrapalemon by Mr. Salter (his Fig. 5), we will remark 
in a supplementary note to this article. 
The only American species we have seent is Anthrapalemon gracilis Meek & Worthen, first 
described in the Proceedings of the Academy of Natural Sciences of Philadelphia, 1865, and 
_ redescribed and figured in the second volume of the Geological Survey of [linois, and again in 
the third volume. 
Mr. Salter figured the carapace aud rostrum, as well as the abdomen of the European species ; 
while the specimen figured by Meek and Worthen evidently did not possess the carapace, but 
showed perfectly the telson and neighboring pair of abdominal appendages. 
The specimens loaned us by Mr. Lacoe enable us to give a more perfect description and illus- 
trations of this important type; and I am indebted to Dr. J. 8. Kingsley tor the restoration and 
*In his Handbuch der Palieontologie, Zittel mentions Pseudogalathea Peach, from the carboniferous of Scotland. 
We have not yet seen Mr. Peach’s article. 
tDr. J. W. Dawson has described and figured, the carapace of Anthrapalamon hillianum, from the Carboniferous 
of Nova Scotia. Geol. Mag., iv, new ser., p. 56, fig. 1, 1877. Also figured in his Acadian Geology, 1878. 
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