CRUSTACEA AND ARACHNIDA OF THE CARBONIFEROUS ROCKS. 513 
flanked on each side by the customary two swimmerets set on a single pro- 
podite, the modified limbs of the sixth segment. The strengthening portion 
of each swimmeret is more elongated than in A. Etheridgii. The test is every- 
where thin and smooth, and devoid of corrugation. Altogether there is a 
chaste severity in the want of external ornament, and an elegance of form 
which makes the abdomen a fit accompaniment to the carapace, and deserving 
of the name it bears. 
Anthrapalemon Etheridgui var. latus, nov. var., Pl. XXVIII. figs, 4-40, 
Among the many specimens of this species, there appears to be a well- 
marked variety, which is in all other respects like A. Etheridgii described by 
me, except that it is much broader and shorter in all its proportions. Its 
breadth compared with its length is as 1 to 24, while in the latter it is as 1 to 3. 
Its carapace is broader than long, while that of A. Htheridgii is the reverse. 
It occurs in the Langholm bed associated with the latter form in the relation 
of about two to every hundred. 
Horizon.—Calciferous Sandstone Series. 
Collector.—A. MACcONOCHIE. 
Rosert ETHERIDGE, jun., of the British Museum, while acting as Paleeonto- 
logist to the Scottish Survey, ascribed several carapaces of a decapod crustacean, 
collected by Mr. Macconocuie from Tweeden Burn, Liddesdale, to the genus 
Anthrapalemon, under the name of A. Macconochi, after the finder. Since Mr. 
ETHERIDGE left, two specimens were found, which displayed many other parts, 
and which I described in my former paper. Further search among the Border 
rocks has brought to light a goodly number of specimens, showing that there 
are at least two more species with a strong family likeness to that form, and 
that they so far agree with it in differmg from all the other crustaceans that 
have been looked upon as belonging to the genus. Their chief characteristic is 
the large size of the carapace compared with the dwindled abdomen, which 
could be of little use as a propelling organ. In this they remind one of such 
recent anamorous decapods as Galathea and Procellana. I therefore propose 
to separate them from Anthrapalemon by forming the new genus Pseudo- 
_ Galathea, to include them, though by so doing I would expressly state that I do 
not believe that our recent Anamoura were more immediately descended from 
these than from any other of the Carboniferous decapods. 
Genus Pseudo-Galathea, gen. nov. 
Character,—Carapace large, subovate or nearly discoid, produced anteriorly 
into short stout rostrum, and the posterior angles continued backwards as 
