INcERT® sEDEs.] LOWER PALALOZOIC RADIATA. 63 
Incerta# SEDES (Probably Echinodermata or Annulata). 
Genus. CORNULITES (Sch.) 
Gen. Char.—Tube gradually tapering, conical, slightly flexuous, most so at the small end, which is 
usually curved, and attached by its sides to foreign bodies ; walls of the tube very thick, cellular, composed 
of numerous imbricating conoidal rings, their widest edge next the slender base, subregular in old specimens, 
more or less distorted or oblique in the young; external surface obscurely annulated, finely striated longi- 
tudinally ; inner surface and casts scalariform, with two or three longitudinal impressed furrows. 
This curious genus differs from Tentaculites in its greater size, being attached, and its irregularities 
of growth and curvature towards the smaller end. The only well-known species is that originally described 
by Schlotheim, the Cornulites serpularius. 
CORNULITES SERPULARIUS (Sch/.) 
Ref-—Schl. Petref. t. 29. f. 7. and Sil. Syst. t. 26. f. 5 to 8. 
Sp. Ch.—Adult tube about three inches long, and eight lines in diameter at the larger end, slightly 
flexuous, curved towards the small end; rings averaging, in decorticated specimens, one line apart in the 
last two inches, being closer and oblique at the narrow end. 
Position and Locality—Common in the Wenlock limestone of Dudley; dwarf specimens about an 
inch long, and two lines in diameter, the rings averaging half a line apart, not uncommon in the Upper 
Ludlow quartzite of Benson Knot and Brigsteer, Kendal, Westmoreland. 
Genus. TENTACULITES (ScA/.) 
Gen. Char.—Shell small, free, straight, regular, slender, conical, tapering nearly to a point; girt with 
numerous thickened circular rings; one (or both‘) ends open, circular; walls moderately thick. 
I can see no reason for believing these bodies to be portions of Crinoids, as suggested by many authors, 
much less spines of Leptena, as suggested by others: their small size, general form, and the appearance which 
large clusters of them often present on the surface of the beds, gives one the idea of their belonging to the 
Pteropoda ; it is not in my power at present, however, to offer any satisfactory opinion on their zoological 
affinities. Their being unattached, small size, and straight, regular form, separate them from the allied genus 
Cornulites. 
TENTACULITES ANNULATUS (Sch/.) 
Ref. and Syn.—Schlotheim, Petrefacten, t. 29. f. 8 + T. scalaris, Id. Id. f. 9. 
Sp. Ch.— Average length ten lines, diameter of the large end one and a third line; girt with numerous 
subequal rings separated by slightly wider concave spaces, four rings in the space of one line near the 
larger end; surface with extremely minute close longitudinal strixe; internal cast, scalariform of a number 
of smooth step-like cylindrical articulations, the projections of which correspond in position to the external 
rings, but so much less prominent that the rings are much the thickest part of the shell. 
The exterior of this species was figured and described by Schlotheim, Sowerby, &ec., as the 7. annu- 
latus, while the internal cast forms the 7. scalaris of the same authors. 
Position and Locality—V ery abundant in the fine Caradoc sandstone of Horderly, W.; Pwllheli, Caer- 
narvonshire ; the Hollies, Church Stretton, Shropshire ; Coniston limestone, Coniston, Lancashire ; Llansant- 
fraid, Glyn Ceiriog, Denbighshire; Ravenstone Dale, Westmoreland. 
TENTACULITES ORNATUS (So7.) 
feef.—Sow. Sil. Syst. t. 12. f. 25. 
Sp. Ch.—Average length seven lines, width at larger end one line ; girt with narrow round rings at 
irregular distances, averaging three in one line at the larger end; intervening spaces broad, flat, and girt 
