SCIENTIFIC SUMMARY. 
95 
GEOLOGY AND PALAEONTOLOGY. 
Crabs in the Coal-measures. — Hitherto the Brachyuran, or short-tailed 
Crustacea, haye been regarded as of comparatively recent origin. Most of 
the known fossil forms have been obtained from Tertiary beds ; and of the 
few Secondary species the most ancient appears to be one from the Forest 
Marble of Malmesbury, Wiltshire, described by Dr. H. Woodward under the 
name of Palceinachus longipes. A specimen just described by the same 
distinguished palaeontologist carries the group of short-tailed Decapods or 
crabs much further back in time ; it is the tail or abdomen of an animal of 
this group from the coal-shale near Mons, in Belgium. This abdomen, which 
is preserved upon a slab of shale bearing impressions of the ferns Neuropteris 
heterophylla and Alethoptei'is lonchitidis, is about half an inch long, and 
nearly perfect. 'It consists of seven segments more or less completely 
anchylosed together as in the Leucosiidae ; its general form is oval, trun- 
cated at the base where it was attached to the cephalothorax. The central 
part or axis of the abdomen consists of a large trapeziform basal segment, 
having a large tubercle on each side of the middle line, and three small 
impressed points near the middle of the hinder margin, followed by five 
smaller, transversely oblong segments, gradually diminishing towards the 
apex, and each marked with three points corresponding to those in the first 
segment. The seventh or last segment is again of large size, and widens in 
a .fan-like form towards the extremity of the tail. The lateral portions of the 
tail, completing its general oval form, are ornamented with tubercles, a 
distinct row of which accompanies each line of division between the 
different segments, and runs out to the edge of the abdomen, where each 
divisional line terminates in a slight projection, giving the margin of every 
segment a gently concave form. For this crab Dr. Woodward proposes 
the name of Brachypyge carbonis. It furnishes the first clear evidence of the 
existence of true crabs during the coal-measure era, although Dr. Woodward 
states that he has received from Mr. M‘Murtrie fragments apparently of 
Brachyura found in the Radstock coal-field, near Bristol, and at the Pendle- 
ton colliery, near Manchester. — Geological Magazine , October, 1878. 
A New Order of Fossil Rhizopods . — Prof. P. Martin Duncan describes 
(Ann. Mag. Nat. Hist. October, 1878), some spheroidal bodies obtained in 
the Karakorum mountains, which he regards as indicating a new order of 
Rhizopods. The fossils are calcareous, and present no traces of having been 
attached during life ; their surface presents rounded or wart-like elevations, 
and sometimes depressions resembling large pores ; and they measure from 
one to three inches in diameter. 
The surface consists of a close reticulation of minute tubes, of the openings 
of such tubes, and of interspaces between the tubes. Internally the fossils 
consist of tubes from ~ to inch in diameter in limited radial groups, 
which are separated by a reticulation of inosculating tubes, such as are seen 
on the surface. The radial groups of tubes form cones with the apex 
towards the centre, and the base usually forming one of the eminences on the 
surface of the fossil. The interradial tubes are derived from the radial ones, 
and the walls of all the tubes are composed of opaque, granular, irregular, 
semi-spiculate-looking, and very minute particles of carbonate of lime. 
