806 K. ETHERIDGE, JUN., OF THE OCCURRENCE OE A 



1854. A celebrated paper appeared during this year by Drs. H. 

 Jordan and H. von Meyer, on Gampsonyx jimhriatus — " Ucber die 

 Crustaceen der Steinkohlcnformation von Saarbriicken " *. They 

 consider Gampsonyx to be an Amphipod with the characters of the 

 Decapoda, especially of the subdivision Macrura. The normal 

 number of somites is fifteen ; and the antennae four, an inner and 

 outer pair, the former double, the latter simple and long. The first 

 pair of feet are strong and longer than the others, and, instead 

 of a chela, are furnished with a small claw-like process. The 

 first pair of appendages is attached to the first or second somite, 

 and the second pair to the third somite. Each of the following 

 segments carries a pair, the fourth to the seventh and perhaps the 

 eighth pair being, like the third, forked. The telson is terminated 

 by two large subdivided caudal appendages. 



1854. A further discovery of specimens resembling Schlotheim's 

 obscure Trilobites problematicas, enabled Baron von Schauroth to 

 propose for it a new genus, Pcdceocranyon f . He describes the 

 cephalothorax, when divested of its outer integument, as divided 

 into a "head-shield" and " breast-shield," the former being the 

 smaller of the two, and overlapped by the latter, which is the 

 largest of all the segments of the body. A smooth sharp keel 

 occupies the median line of the head- and breast-shield ; and the body- 

 segments also show traces of it. The front of the head- shield is 

 ornamented with knotty elevations, whilst the breast-shield is in 

 places shagreened. On the posterior portion of the breast-shield 

 there is a transverse swelling parallel to the first body-segment. 

 The carapace (= head- and breast-shield combined) is somewhat 

 triangular in profile, and on its outer surface is shagreened and 

 besprinkled with tubercles. The body -segments are small, and are 

 convex in their anterior half and concave in their posterior half. 

 Von Schauroth considers that the general form, the median keel, 

 and segmented body indicate an affinity with the Decapoda ; the 

 form and order of the body-segments remind one of the Isopoda. 

 Prom the Zechstein dolomite of Gliicksbrunn. 



1854. Sir W. Trevelyan, in an Address to the Members of the 

 Tyneside Naturalists' Pield-Club, at their eighth anniversary 

 meeting, announced the discovery by Mr. J. W. Kirkby of the tail 

 of a Macrurous Crustacean in the Permian Limestone near Sun- 

 derland j. 



1854. In the second volume of his ' Traitc de Paleontologie ' &o., 

 Prof. F. J. Pictet, under the heading " Decapodes mal connus," 

 places the Devonian Gitocrangon granulatus, llichter §. Gampsonyx 

 was regarded by him as an Amphipod ; and he remarks that, if 

 Jordan's description is correct, it should be so regarded, or as an 

 Isopod, and not as one of the Macrura, as placed by Bronn |J. 



* Palreontographica, Jan. 1854, vol. iv. pp. 1-16, pi. i. 



t "Em Beit rag zur Palaontologie des deutschen Zeclisteingebirges," Zcitsclirift 

 d. deutschen geol. Gresellsckaft, vol. vi. p. 5(50. 



% Trans. Tyneside Nat. F. Club, vol. ii. 1851-54, p. 333. 

 § 2nd edition, vol. ii. p. 461. 

 || Ibid. p. 464. 



