KONTNCK NEW PAL.^IOZOIC CRINOIDS. 



179 



preceding, rather thick, and separated from each other by a strong groove. 

 The second radial plates are also pentagonal, and broader than long. The axillanj 

 plate is very thick, and furnished with a slight protuberance, and juts outwards. 

 The brachial plates, which follow the axillary plate, olfer nothing remarkable. The 

 external surface of these plates is indented with little irregular tracings, which 

 make it rough, and the test thus resembles shagreen. The arms — twenty in num- 

 ber — are composed of cuneiform alternating articulations, and are joined together 

 laterally. I have not observed any traces of pinnules. The little plates of which 

 the dome is composed are all ornamented with a prominent tubercle in the middle. 

 Their surface is apparently smooth, their number variable, and their form is 

 generally hexagonal, i have not been able to discover any traces of a horn or 

 proboscis, nor of any anal or buccal opening. It is probable these were situated 

 between the arms, which were placed on the anal or irregular side of the bulb, 

 and that these arms were capable of extension, and of admitting a passage for the 

 food of the animal. The stem is rather stout, in comparison to that of most of 

 the other species, among which it is often very slight. 



Dimensio7is — The total length of the bulb is about 40 millemetres ; diameter, 

 25 mm. ; length of calix, 12 mm, ; diameter of stem, 4 mm. 



Affinities and Differences. — This species, by the form of its calix, 

 approaches to H. granulatus, Phil, and H. Phillipsianus, Be Kon. It is 

 distinguished from them by the thickness and convexity of its different 

 plates, as also by the rugosity of its surface, which is granulose in the 

 first, and perfectly smooth in the second. 



This species was discovered by my excellent friend, Mr. Edw. Wood, 

 in the ferruginous beds of the carboniferous limestone in the neighbour- 

 hood of Eichmond, in Yorkshire. In dedicating it to him, I only feebly 

 acquit myself of the debt of obligation which I owe to him for the mag- 

 nificent specimens obtained through his indefatigable researches, and 

 with which he has so kindly enriched my collection. 



Explanation of figures — PI. lY. : — 



Fig. 5, — Complete specimen, view of the anal side, slightly restored, and of the 

 natural size. From the collection of Mr. Ed. Wood, of Richmond, Yorkshire. 

 Fig. 5a. — Dome, slightly enlarged, from a specimen in my collection. 



2. Hydreionocrinus Scoticus. Be Koninch. PI. IV., fig. 6, 7. 



As yet I know of this species only the calix. This is rather small, very 

 short, and saucer-shaped. Its hasal plates are very small, plain, and quadrilateral 

 in form. By their grouping they produce a regular pentagon, in the centre of 

 which may be observed the articular face of a tmall cylindrical stem. The suh- 

 radial plates are rather large in comparison with the hasal, which are a little less 

 long than broad, very convex at the centre, thus forming a protuberance sufficient 

 to produce a very decided depression at the base, which remains perfectly 

 concealed when the calix is placed on a flat surface. The first radial plates are of 

 pentagonal form, and nearly twice as broad as long. They are slightly less arched 

 than the preceding plates, but in all the species of the same genus they are situated in 



