Manchester Memoirs, Vol. liii.{\(^og\ No.'%%. 5 



together would appear to indicate the presence of several 

 species. 



Figs. 10, II, and 12 show some individual prints 

 of these forms which indicate the form more clearly. 

 In all of them the impression of the "sole" appears 

 to be incomplete {cf. ChelicJinus ambigims, Plate III., 

 Fig. 21). It is improbable that these three figures belong 

 to really identical forms, but until better material is 

 available I think it is better to group them together under 

 the title a. 6.* 



Lacertoid form. — Fig. 14 represents a very interesting 

 isolated print on one of Mr. Varty Smith's slabs. It is 

 unlike any other British Permian impression I have seen, 

 but it agrees with certain impressions from the Thlir- 

 ingian Permian, and from the Kansas Coal Measures, in 

 possessing 5 slender curved digits, with ball-like pads, 

 the fifth being " thumb-like," and in having little or no 

 trace of a " sole." This type of foot is very characteristic 

 of modern lizards, and I think the term " lacertoid " may 

 be aptly applied to it. This print will therefore be Lc. i. 



Other forms. — Fig. 9 has already been mentioned as 

 nearly identical with ,t"3 from Mansfield. In many of the 

 impressions, the fifth digit (left in the figure) is absent, 

 and the agreement is then very marked. Only the 

 difference of locality, and a slight difference in size, lead 

 me to provisionally separate it. The track is almost 



* Note. — Since writing the above I have received a photograph of the 

 slab on which I found the original of Fig. 12, and which I was not able to 

 examine fully in the quarry. It is now possible to trace the track to which 

 the print belongs, and to see that this form is not, as I had supposed, allied 

 to those shown in Figs. 10 and 11, but is a Herpetichnoid form, having the 

 toes turned inwards nearly at right angles to the track. It must therefore 

 be designated Hp. 3. 



This instance serves to illustrate the necessity for observing prints in 

 tracks, and not merely individually. 



