TRANSACTIONS OF THE SECTIONS. 77 
Dubiin, on one of the specimens first discovered, which he proposed should, as well 
as the allied and probably contemporaneous forms found in ironstone nodules from 
the Penney stone of the lower coal-measures, Coalbrook Dale, hitherto included in 
the genus Limulus, be removed from the recent genus, as presenting characters more 
closely allied to Trilobites, and to which new genus the name of Steropis was given. 
Since then, however, more perfect specimens and another species had been obtained 
by himself and Mr. Kinahan, which had still further confirmed his views respecting 
the necessity for a rearrangement of the genus; and as one of the most common 
species was originally figured by Konig in his ‘ Icones Sectiles’ in 1825, by the name 
of Bellinurus bellulus, he considered it but just to restore that generic name in pre- 
ference to adding a new one. These Coal-measure Crustacea appearing to be the 
commencement of the Limuloid type, it was thought advisable to consider them as a 
subgenus of Limulus under the name of Bellinurus. 
The nomenclature would therefore be the following :— 
Order ENTOMOSTRACA, 
Legion Pacitropopa, Order Xiphosura. 
Genus Limulus, Miiller; subgenus Bellinurus, Konig. 
Bellinurus (Limulus) anthrax, Prestwich, Geol. Trans, 2nd ser. 5, t. 41. f. 1-4. Coal- 
measures, Coalbrook Dale. 
Bellinurus (Limulus) rotundus, Prestwich, Geol. Trans. 2nd ser, 5. t. 41. f. 5-7. Coal- 
measures, Coalbrook Dale. 
Bellinurus (Limulus) trilobitoides, Prestwich, Geol. Trans. 2nd ser. 5. t.41. f.8; and 
Buckland, Bridgw. Treat. p.396. t. 46”. f.3. Coal-measures, Coalbrook Dale, 
Also Col. Portlock, Report on Londonderry, &c. t. 24. f. 11, doubtfully referred to 
this species. 
Synonyms of this species—(Entomolithus monoculus), Martin, Pet. Derb. t. 45. f. 4. 
(Bellinurus bellulus), Konig, Icon. Sect. pl. 18. No. 230. 
{In Parkinson’s ‘ Organic Remains,’ vol. iii. pl. 17, a similar fossil is said to be 
figured from Dudley: vide Buckl. Bridgw. Treat. ] 
Bellinurus Regina, Baily, u. sp. Coal-measures, Bilboa Colliery, Queen’s Co. 
Bellinurus arcuatus, Baily, n. sp. Coal-measures, Bilboa Colliery, Queen’s Co. 
Descriptions of these two new species were given by Mr. Baily ; Bellinurus Regina, 
which was of small size, being remarkable for having had the cephalic shield and 
thoracic rings extended into long spines; these diminished in regular gradation 
towards the tail, which was small and bore a spine of great size and length, being 
three times that of the animal. 
Length 1 inch and 3th. Breadth } inch and 3,ths. Length of tail-spine “ths 
of an inch. 
The second species, Bellinurus arcuatus, was said to be allied to B. trilobitoides, 
but differed in its general form and the greater spreading out of the spines at the 
posterior angles of the cephalic shield; also in the development of two additional 
spines from the ridge of the glabella extending over the body, 
Several specimens of this species were obtained; one from a concretion in the shale 
exhibited the form of the body, which was broadly ovate and acuminated posteriorly, 
having a moderately developed tail-spine; it showed distinctly the division of each 
thoracic ring into segments, having grooved lateral angles, as in the Trilobites. 
Length l inch. Breadth 48ths of an inch. Length of tail-spine about $ an inch, 
Mr, Baily then alluded to the great paleontological interest attached to the dis- 
covery in Ireland of new forms of Coal-measure Crustacea so similar in character to 
those found at Coalbrook Dale, Shropshire, by extending their distribution to corre- 
sponding strata in that country, and indicating similar conditions to have been preva- 
lent over a wide area, 
On a comparison of these Coal-measure Crustacea with the more recent and living 
forms, the wide gap in point of time corresponds with the great difference observable 
in their structure, which exhibits a closer alliance with the Trilobites. On the con- 
trary, there is a striking resemblance between the Upper Jurassic remains, which are 
those of true Limuli and the living forms. 
