﻿102 BRITISH FOSSIL CEPHALOPODA. 



its rings. This last character is repeated in 0. kendalense, but in that the septa and 

 rings are closer still. Both one and the other specimen leave a doubt upon one's 

 mind whether they may not rather be Crinoids than Cephalopods. 



Distribution. — In the Ludlow Passage Beds, Newton Lane, Kington (I). 



Orthoceras Grayi, Blake, PI. XIII. fig. 6. 



Type. — The section is elliptic, the diameters being in the ratio of 5 to 4. The 

 rate of increase of the long diameter is 1 in 5. The whole is septate. The 

 ornaments are sub-acute, sub-separate ribs, 2° or 3° oblique on the narrow side, f the 

 long diameter apart. The specimen is too rough to show any finer ornaments, if 

 they existed. The septa are oblique in the opposite direction to the ribs, and to 

 about the same amount ; they are closer than the ribs, being about \ the long diameter 

 apart. The siphuncle is not well seen, but appears to be central. Length, If inches ; 

 greatest diameter, 1 inch. From the Wenlock Limestone, Dudley. In the Gray 

 Collection in the British Museum. 



General Description. — No example but the type shows the characteristic relation 

 of the septa to the ribs ; but as there are specimens agreeing with this in outward 

 features, associated in the same locality, and not belonging to other known species, it 

 may be assumed that they belong to this. No section is seen in them, and the rate 

 of increase is much slower, not being more than 1 in 10, in a larger though flattened 

 example. The ribs are in one •§ and in another f the diameter apart, slightly oblique 

 on the narrow side, of the separate semi-acute character, and covered in two examples 

 with fine parallel riblets. These have diameters of more than 1 inch. Still larger 

 examples, possibly of this species, show very strong ribs, and the riblets are upward 

 imbrications. 



Relations. — The peculiar septal characters which are uncommon in Orthocerata, 

 belonging to this group, immediately separates the type from other species, though 

 a want of parallelism between the septa and ribs, in some examples referred to 

 0. ibex, leads us towards such peculiarities. When the surface only is seen, the 

 chief distinguishing features are the rate of increase and the large size. The 

 absence of any festooning in the finer ornaments separates this externally from 

 0. annulatum. 



Distribution. — In the Wenlock Limestone of Dudley (4). Examples of this 

 species are in the British and Woodwardian Museums. There are also two 

 specimens from the Lower Ludlow of Ledbury (2) in the collection of Dr. Grindrod, 

 which only differ from 0. annulatum in the transverse riblets showing no sign of 

 festooning, and which may therefore more probably belong to this species. 



