THOLIASTERELLA. nye 
and cylindrical form of the spicular rays and the less development of the central 
disc. 
Distribution—Carboniferous : Upper part of the Lower Limestone series, Law, 
Low Baidland, Dalry, Ayrshire. (J. Smith, J. Bennie.) 
47. THOLIASTERELLA compacta, Hinde, sp.nov. Plate VII, figs. 3, 3 a. 
The dermal skeleton of this species is a thick, perforated plate, consisting of 
*umbrella-”’ shaped spicules, with stout conical shafts, and five or six robust, 
cylindrical transverse rays. These completely fuse and amalgamate with those 
of adjoining spicules, and they are so closely arranged that only a few small circular 
or oval apertures are present between the rays. The upper surface of the spicule, 
forming the exposed surface of the dermal layer, is thickly covered with numerous 
minute, blunted tubercles. 
This perforated dermal layer is from 1 mm. to 1°3 mm. in thickness, whilst the 
entering shafts of the spicules in some instances are ‘3 mm. in length. Ina 
specimen belonging to Mr. John Smith, a portion of the internal skeleton is pre- 
served in connection with the dermal layer. It apparently consists of relatively 
large spicules of an irregularly stellate form, the rays are of unequal length, 
conical, and often furcate at their ends. These spicules are intermingled together 
without definite arrangement, and the rays are frequently fused at their points of 
contact with adjoining spicules. 
The complete fusion of the spicules of the dermal layer, and the irregular form 
of the skeletal-spicules, distinguish this from other species of the genus. 
Distribution.—Carboniferous : Upper part of Lower-Limestone series, Cunning- 
ham Baidland, Law Quarry, Dalry, Ayrshire. (J. Bennie, J. Smith.) 
48. THOLIASTERELLA crassa, Hinde, sp.nov. Plate VIII, figs. 5,5a; Plate IX, 
figs. 2, 2a—2 b. 
Skeleton consisting of very robust “ umbrella ”’ spicules, with conical or elongate 
cylindrical shaft, and from five to six transverse rays. These rays are cylindrical 
or conical, straight or curved, horizontal or diverging irregularly from the central 
disc. Asarule the transverse rays are very unequally developed, some being 
mere conical points, whilst others in the same spicule are relatively very long. 
The rays are smooth, and either simple, or with stout, obliquely placed spines, 
