Mr. W. H. Baily on some Coal-measure Crustacea. 107 



the joint, have disappeared ; on the other hand, the uterus, with 

 its ova, immediately makes its appearance. In this case, how- 

 ever, it does not present, as in other Tcenice, the characteristic 

 form, already often compared to a stem and branches, but only 

 forms a sac densely filled with ova, and occupying the whole 

 joint. Each joint contains about 100-150 eggs. The fully 

 developed ova are elliptical, 0*0560 mill, in length and 0*0455 

 mill, broad ; they present three envelopes, of which the outer- 

 most is smooth and transparent, the intermediate one very thin 

 and slightly folded, and the innermost one, which is closely ap- 

 plied to the embryo, 00035 mill, in thickness. The diameter 

 of the six-hooked embryo is 0*0315 mill. ; the distinctly percep- 

 tible embryonal hooks are 00105 mill, in length. 



The second Tania met with in the Shrew, which I will call 

 T. fwcata, on account of the forked form of its hooks, is very 

 rare. Its length is 8-10 mill. ; the round head, distinctly 

 separated from the neck, is 0*151 mill, in breadth, and possesses 

 four sucking-disks and a short proboscis, which is furnished 

 with a circlet of from twenty-two to twenty-eight hooks. The 

 neck is 210 mill, in breadth. The width of the segments 

 increases gradually with the length, so that the broadest seg- 

 ments are 0*56 mill, in breadth and 021 mill, in length : the 

 last joints, from which the ova are already removed, exhibit 

 smaller dimensions; they are 0*280 mill, broad, and 0*105 mill, 

 long. The number of distinctly recognizable segments is 100. 

 The genital orifices are all on one side. 



The hooks are distinguished by a long and thin root-process, 

 which is clearly separated from the true hook-process. The 

 distance from the root-process to the apex of the hook is 0*024 

 mill.; the apex of the hook is distant 0005 mill, from the distal 

 process, and the two processes are 0*0210 mill, apart. 



With regard to the sexual organs and the ova, I have nothing 

 to add, as all that has been said of T. uncinata applies also to 

 this Tcenia. 



XVI. — Remarks on some Coal-measure Crustacea belonging to the 

 Genus Belinurus, Konig ; with Description of two new Species 

 from Queen's County, Ireland. By William Hellier Baily, 

 F.G.S.* 



[Plate v.] 



The generic term Belinurus was applied by Konig, in 1820, to a 

 pecuhar Crustacean from the Coal-measures, figured and named 



* An abstract of this paper was read at the Meeting of the British 

 Association in 1858. 



8* 



