88 B. N. PEACH ON SOME NEW CRUSTACEANS FROM THE 
In the interval between the reading the present paper and its printing, I 
have been enabled to study several more Carboniferous Macrura. Some new 
species of Palewocragon, each showing the swimming flaps flanking the telson and 
articulated with it; also a large suite of fossils of macrurous decapods inter- 
mediate between Palewocaris and Anthrapalemon, in having only two or three 
of the thoracic segments covered by the carapace, and the sterna of these not 
soldered together, and they all exhibit the spines or flaps on the telson. The 
small spines articulated at the posterior angles of the telsons of our recent 
shrimps and prawns are evidently a survival of what has once been a useful 
character of their more ancient progenitors. It seems a pity to disturb the 
seemingly satisfactory and complete number twenty for the segments of the 
typical crustacean by adding another to make it twenty-one, but the present 
evidence favours the latter number. 
Note 2.—Since the above was written, a paper read by M. P. Broccutr before 
the Geological Society of France, in Nov. 1879, and published in the Bulletin 
of that Society in March 1880, on a “ Fossil Crustacean, from the Schistes 
d’Autun ” (Upper Carboniferous or Lower Permian), has come before my notice. 
After a careful perusal of his paper, I have not been able to satisfy myself with 
the conclusions M. Broccut arrives at regarding the systematic position he assigns 
to the genus Paleocaris, Meek and Worthen, which he includes in his new 
division of the Amphipoda, the Nectotelsonides. His reasoning, based upon the 
first thoracic limbs not being modified into prehensile organs, disappears in the 
light of such forms as Anthrapalemon Traquairii and A. Etheridgii described in 
the above paper, or the recent Palinurus vulgaris, whose limbs are not so modified, 
but in which the decapod characters are undoubted. Such evidence as the 
specimens of P. Scoticus afford are in favour of decapod affinities, and I there- 
fore retain the classification latterly adopted by Messrs MEEK and WorrTuHEN, 
which M. Broccut has apparently overlooked.* 
* Memoirs of the Geological Survey of Illinois, vol. iii. p. 552, 1868. 
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