On Some Carboniferous Arthropods. 147 
thoracic limb, is seen to project beyond the pleura of the fifth and sixth 
trunk segments. 
Behind the last thoracic segments the body suddenly narrows, the tail 
segments becoming longer and narrower as they are followed backwards, and 
very slender near the insertion of the telson. The pleura of these segments 
are inconspicuous, and not nearly so well developed as those of the thoracic 
segments. Three of these segments still bear many-jointed pleopods, both 
branches of which are preserved, one of these limbs on the fourth tail 
segment. The tail fan is made up of a short sub-quadrate telson, flanked 
by much longer knife-blade-like uropods, representing the exopodites of the 
limbs of the sixth segment. The endopodites are not observable, being either 
small and delicate or not present. The whole arrangement of the tail fan 
is similar to that found in the Mysids. 
These remains have been provisionally placed in Meek and Worthen’s 
genus Paleocaris, but owing to the state of preservation it would be 
injudicious to give to them a specific name. 
Locality.—-South Staffordshire Coalfield. 
Horvzon.—Coal Measures. 
Division PERACARIDA, Packard, 1879. 
Family LOPHOGASTRIDZ, Sars. 
Genus Pygocephalus, Huxley, 1857. 
Pygocephalus coopert, Huxley, Quart. Jour, Geol. Soc., 1857, [Pl. IV. Figs. 10-12.] 
In his paper published in the Geological Magazine for 1907, Dr Henry 
Woodward figures two specimens of P. coopert showing remains of two 
females with the breeding lamellie in place,! thus proving that these forms 
had their proper place among the Mysids, as had already been suggested by 
Huxley as far back as 1857.? 
In the Gubbins Collection is a third specimen of a female with breeding 
lamellee in situ, which exhibits points not hitherto described. Fig. 10 shows 
the ventral view in relief, the dorsal portions being embedded in the iron- 
stone nodules, all except the tail, which is characteristically folded over the 
hinder part of the thorax. Fig. 11 is the counterpart of the same specimen 
in intaglio. The chief points shown in the present specimen is the remark- 
able state of preservation of the antennular and antennary systems, and the 
mandible with its palp. The arrangements of these parts is quite caridean. 
For the purpose of illustrating this point Figs. 12 and 13 have been drawn. 
1 Geol. Mag., vol. iv., new ser., pp. 400-407, pl. xviii., 1907. 
* Quart, Journ. Geol, Soc,, vol, xiii, pp. 363-369, pl. xiii, 
