442 G. C. Crick — On Coccoteut/iis, Solenhofen. 



of the body, so that the anterior part appears to have been 

 possibly for a width of about 5 mm. continuous with the posterior 

 portion. This boundary curves gently outwards and upwards 

 to the edge of the slab containing the fossil. The width of the 

 expansion that is preserved is about 37 mm. ; it is fairly smooth, 

 with very obscure transverse striation, the rest of the surface 

 of the slab being somewhat roughened and also of a lighter colour ; 

 its outer boundary was removed in reducing the specimen before 

 it came into the National Collection. The anterior boundary (/) 

 seems to be indicated by a faint line of colour arising from the 

 margin of the body at a point 56*5 mm. from the posterior end ; 

 it curves outwards and rather abruptly forwards, and can be traced 

 for about 17 mm. The antero-posterior length of this expansion at 

 the margin of the body is 44 mm. 



On the left-hand side of the specimen a portion of the lateral 

 expansion is also shown, but unfortunately a much greater part than 

 on the right-hand side has been removed in reducing the slab. 

 The posterior portion has about the same antero-posterior dimension 

 as on the other side, but appears to have been only about 125 mm. 

 wide; its posterior boundary (/'), which is well preserved, is 

 slightly curved and nearly at right angles to the median line of 

 the body. On this side, too, the posterior boundary of the anterior 

 larger portion cannot be traced to the margin of the body, and 

 appears to support the idea that the two portions of the lateral 

 expansion were continuous for a short distance from the margin of 

 the body. The posterior boundary 1 of the larger portion curves like 

 that on the opposite side of the body, but is intercepted by the edge 

 of the slab at a width of about 16 mm. The anterior boundary (/) 

 arises at about 57-5 mm. from the posterior extremity of the body, 

 passes outwards and upwards to the edge of the slab at an angle of 

 about 45° with the median line of the body. 



Only portions of the internal shell are preserved, viz., the anterior 

 portion, part of one of the sides, the greater part of one of the 

 wing-like expansions, and the impression of the other expansion, 

 but these are quite sufficient to indicate the complete outline of the 

 shell. It is lanceolate-oval in form, 95 mm. long and 29 mm. in 

 width, excluding the lateral expansions. The hinder three-sevenths 

 (about 40 mm.) is provided with wing-like expansions ; its greatest 

 width, including these, is 41 mm. at about 28 mm. from the posterior 

 extremity. There is no trace of the ink-bag. The head, with the 

 arms, has a length of 85 mm. The greatest width of the head is 

 81 mm. On the right-hand side there is a mass of calcite, a portion 

 of which possibly occupies what was the orbital cavity (e). About 

 in the centre of the head there is a triangular indentation (b). having 

 its apex directed forward and a little to the right side ; this is 

 without doubt the impression of one of the mandibles or " beaks." 



Eight arms can be made out ; they do not differ greatly in size. 

 There appears to be no trace of the tentacular arms, but such may 



1 This is scarcely visible in the figure. 



