REVIEWS. 303 
materials for the sixth volume are being prepared for publication 
as rapidly as possible. These two volumes will include the reports 
on the remaining counties in the state, and will complete the sur- 
vey in accordance with the plan hitherto pursued. 
New FossıL Crustacea.*— Mr. H. Woodward, who has brought 
to the notice of naturalists so many crustacea of the older forma- 
tions especially, describes and figures a new species of Scyllaridia 
( llii) from the London clay. The genus is allied to the 
modern Scyllarus, an ally of the Spiny lobster (Palinurus). An- 
other interesting form, also figured, is allied to the fish louse, Aga. 
It is called the Palega Carteri, and is from the Cretaceous forma- 
tion. 
Of the greatest interest, however, are the figures and descrip- 
tions of several species of Cyclus from the Carboniferous formation 
of Great Britain. These singular and puzzling forms are round, 
hemispherical, with the body trilobed, and with well marked seg- 
ments and deep sutures between them. They are from two to five 
lines in length. Goldfuss originally figured one species as a 
trilobite (Olenus serotinus), and afterwards Miinster referred it to 
Limulus ; while Von Meyer believed it to be neither. Koninck, 
however, placed it among the aberrant trilobites near Agnostus. 
In 1868 Woodward said of it, ‘“ we must differ from M. de Koninck 
in referring this form to the Trilobita. If truly an adult, it must 
be placed near to Apus, with the other shield-bearing Phyllopoda ; 
if a larval form, it may have been the early stage of Prestwichia 
or some other of the Coal Measures Limulide.” In the present 
notice Mr. Woodward reiterates his opinion that “these forms 
may indeed be the larval stages of Prestwichia, Bellinurus, etc., 
the antetypes in Carboniferous times of the modern king crab.” 
In agreeing, so far as we can judge from the figures, with this 
view, we may say that Limulus sometime before hatching passes 
through a globular, hemispherical form, with deeply marked sut- 
ures, like those observed in several species of Cyclus. Thus 
‘the embryonic condition of the modern king crab, was, during the 
Carboniferous period, probably the mature, or at least larval (not 
embryonic) condition of the Cyclus. A study of these highly 
interesting forms will undoubtedly throw light on the affinities of 
both the king crabs and the trilobites, and indicate that they are 
* New British Fossil Crustacea. Extracted from the Geological Magazine, London, 
1870. Nos. 11 and 12. With two plates and wood-cuts. pp. 5 and 7. 
