Messrs. Jones and Kirkby on Carboniferous Entomostraca. 33 



and polished, was the most numerous of those mentioned ; an- 

 other, also white and polished, but larger and scarcer, is sub- 

 triangular, and evidently a Bairdia (fig. 20), somewhat crushed 

 — a condition noticed by Ure; it was rare, in a limestone-quarry 

 fifteen miles west of Newcas tie-on -Tyne, near the spot where 

 the Roman wall is intersected by Watling Street. Figs. 16,17, 

 and 21 are given as different views of one form, the scarcest of 

 all : fig. 21 is certainly a Kirkbya badly drawn ; and the other two 

 are Beyrichian in appearance {Beyrichia bituberculata, M'Coy, 

 sp.). 



Among the mounted specimens in the Hunterian Museum 

 are Leperditia Okeni, Miinster, var., Cytherella, Bairdia curtttf 

 M'Coy, B. subcylindrica, Miinster, and the Kirkbya roughly in- 

 dicated by lire's fig. 21, which is K. Urei, Jones (Trans. Tyne- 

 side Nat. Field-Club, 1859, p. 136; and Gray's 'Biograph. 

 Notice,' &c., p. 52). 



Dr. Ure's microscopic specimens seem to have been collected 

 chiefly at Lawrieston and Stuartfield (East Kilbride). It is only 

 of late that the energetic geologists of Glasgow have been able 

 to rediscover the exact strata which yield them. In a letter 

 dated July 4, 1865, our friend Mr. John Young, of Glasgow, 

 states — 



" Since I began to pay any attention to the collecting of 

 Entomostraca, I have often searched for the bed in which David 

 Ure obtained the specimens figured in his book, and also mounted 

 in the Hunterian Museum in London and in the collection of 

 the Andersonian Institution in Glasgow ; but as the quarries 

 from which he got them have been filled up, and as Ure does 

 not tell the nature of the strata from which he collected them, 

 I have never been able to find them until the last v/eek or two. 

 In examining some shale from the Calderside old limestone- 

 quarries, near High Blantyre, Lanarkshire, I was fortunate in 

 again discovering Ure's bed for the Kirkbya, &c. It lies between 

 two beds of limestone, which crop out in both Blantyre and East 

 Kilbride parishes. This bed of shale is loaded with organisms 

 in a more or less perfect condition, namely Corals, Polyzoa, 

 Brachiopoda, Conchifera, Crinoids, Bivalve Entomostraca, Tri- 

 lobites, &c. The shale soon breaks up on exposure to the 

 weather, and then the minute organisms can easily be extracted 

 from it by washing." Mr. John Young then refers to some 

 mounted specimens of Bairdia, Kirkbya, Cytherella, and Fora- 

 minifera, from this shale, that were kindly sent in his letter, and 

 adds, " I find, on comparing the figures given by Ure with the 

 Entomostraca from Calderside, that he has made a mistake in 

 confounding two distinct forms as belonging to the same spe- 

 cies. Figs. 16, 17, and 21 he thought were the same. I find 



Ann. ^ Mag. N. Hist. Ser. 3. Vol. xviii. 3 



