3840 MM. Wilson & Crick—The Lias Marlstone of Tilton. 
OnyouiTzs, sp. Plate X. Fig. 6. 
Two of the peculiar bodies known by this name were obtained by 
Mr. B. Thompson, F.G.8., from the East Norton-embankment. 
The specimen here figured may be described as follows: Cylin- 
drical curved hollow body tapering to a point at each end, somewhat 
constricted in the middle (8 mm. in diameter) and expanded towards 
the ends (4 to 5 mm. in diameter), and flattened and with acute 
edges towards one end; this body is bow-shaped, the points curving 
towards the same side, but in planes considerably inclined to each 
other ; the pointed ends are about 4:5 centimetres apart; the shelly 
covering is thin, smooth and apparently structureless, but under 
a high-power lens its external surface appears to be finely 
punctated; the shell is separated from the surrounding matrix by 
a uniformly narrow hollow space about -5 mm. broad, indicating 
apparently the former presence of a soft investing organic layer, 
which has disappeared in the process of fossilization. At first sight 
these hollow cylindrical bodies look as if they might have belonged 
to tubicolar Annelids; but it is to be observed that their tubes are 
closed at both ends, ane that, as we have just seen, there are indica- 
tions of their having been internal and not external structures. 
Thirty years ago, Quenstedt described several of these curious 
bodies in “Der Jura.”! At one time it appears they were taken 
for ‘compressed crabs-claws”’! Dr. Fraas considered them to be the 
acetabular hooks of Cephalopods, referring them to Onychoteuthis, and. 
in this view Quenstedt concurred. Messrs. Tate and Blake state in 
‘The Yorkshire Lias’*? that they met with these pointed organisms 
in the ‘Jamesoni beds’ at Peak, agreeing with the Onychites 
numismalis, of Quenstedt, but they avoided any speculation as to 
their true nature. I am inclined to accept the explanation suggested 
by Fraas and Quenstedt. 
Marlstone Rock, Tilton (Hast Norton embankment). 
EXPLANATION OF PLATE X. 
Fic. 1. Cardinia Slatteri, Walford. Marlstone Rock, Tilton (East Norton 
embankment). Left valve, exterior. Nat. size. 
a Nes Ibid. Marlstone Rock, Transition-bed, Appletree. Right 
valve, interior. Nat. size. 
sot kos Pinna Tiltonensis, sp. nov. Marlstone Rock, Tilton (East Norton em- 
bankment). Nat. size. 
5» 4, 4a. Inoceramus, sp. Marlstone Rock, Tilton (Hast Norton embankment). 
Right and left valves. Half nat. size. 
», 5. Hodiadema granulata, sp. nov. Marlstone Rock, ‘Tilton (East Norton 
embankment). Side view, enlarged twice. 
OL Tbid. Apical system. Same locality. “Enlarged six times. 
59, OO Ibid. Mouth opening. From another specimen, enlarged 
three times. 
ap BS Ibid. Ambulacrum and interambulacrum, enlarged six times. 
Os Onychites, sp. Marlstone Rock, Tilton (East Norton embankment). 
1 « Der Jura,” p. 201, pl. 24, fs. 59-62, and pp. 246-7, pl. 34, fs. 2-6. 
2 «© The Yorkshire Lias,’’ p. 448. 
