34 Messrs. Jones and Kirkby on Carboniferous Entomostraca. 
that figs. 16 and 17 are intended to represent Beyrichia bituber- 
culata, M‘Coy, sp., which is sparingly found in the Calderside 
shale together with Kirkbya Urei, Jones, which Ure produces 
in fig. 21. It is strange that he should have made this mistake, 
as the two shells are quite distinct to the naked eye under every 
aspect.” 
1834. Hibbert.—In 1834, Dr. Hibbert brought to the notice 
of the British Association at Edinburgh, and in1836 he described, 
in the ‘Transactions of the Royal Society of Edinburgh’ (vol. 
xill.), some Entomostraca from the Carboniferous strata near 
Burdiehouse, which are rich in these minute carapaces, mostly, 
however, belonging to one species*. At page 179 of his memoir 
he gave small woodcut figures of his Cypris Scotoburdigalensis, 
and at page 180 others of his Daphnoidia. The latter received 
the name of “ Hibberti” in Morris’s ‘ Catalogue of British Fos- 
sils,’ first edition, 1843. Dr. Hibbert’s specimens were again 
noticed by Mr. L. Horner in the ‘ Edinburgh New Philosophical 
Journal’ for April 1836, and were regarded as indicating an 
estuarine (and not a freshwater) origin for the strata containing 
them. 
Among the many Carboniferous specimens lent to us by our 
friend Mr, KE. W. Binney, F.R.S., are several bearing minute 
Entomostraca that were in Dr. Hibbert’s collection. In these, 
* Cypris Scotoburdigalensis” is abundant ; but Daphnoidia, un- 
fortunately, does not appear. Nor can we form a satisfactory 
conclusion as to the nature of this little fossil from Dr. Hibbert’s 
woodcuts. The so-called ‘‘ Cypris” is readily recognized to be 
a dwarf Leperditia, with the characteristic muscle-spot, and 
possessing even the hump on the back of the left valve, so 
marked a feature in some members of that genus. Excepting 
in relative size, no distinction can be discerned between Leper- 
ditia Scotoburdigalensis and L. Okeni; and we find very many 
gradations in size among these little Leperditie of the Carboni- 
ferous shales and limestones, including L. Okeni as a large form 
and L. Scotoburdigalensis as the smallest. Two or more of these 
varieties are often associated together, sometimes probably as 
young and old conditions, but often as varieties determined by 
mode of growth. Some slight differences in the outline of the 
valves, or in the profile of the carapace, occasionally accompany 
variation in size; and, taking these together, we use them as 
* In more than one of the many samples of the Burdiehouse limestone 
and shale that we have examined, we have noticed what appears to be a 
more elongate (and Cythere-like) form than Leperditia Scotoburdigalensis; 
but the specimens are so imperfect as not to be determinable. We may 
say the same in respect to other crushed specimens from this locality, that 
resemble Beyrichia subarcuata, Jones. 
