H. A. Nicholson — On the Lake District. 167 



Locality and Formation. — In the zone of Ammonites angulatus. 

 Lower Lias ; Island Magee, Co. Antrim. 



BemarTcs. — The only Belemnites in the Lower Lias of Ireland are 

 B. acuius, Miller, and B. pencillatus, Sow., which occur in strata 

 newer than the zone of Ammonites Bucldandi, which intervenes be- 

 tween these Belemnite beds and the zone of Ammonites angidatus, 

 whence B. prcematurus was obtained. Naturally the question arises, 

 laay not this form be the young state of one or other of these species, 

 but the presence of lateral furrows in £. prmmaturus precludes such 

 ;a relation. The affinity to B. clavatus is more obvious, but it has 

 not the elegant fusiform outline of the young of that species ; how- 

 ever, the smallest specimen of B. clavatus, Bl., with which I have 

 compared B. prcematurus, is not less than one inch in length ; my 

 species has more of the form of B. dorsalis, Phillips. 



The uncertain value of specific determinations based on immature 

 specimens must apply in great force to the species I have described ; 

 yet on the other hand insignificant characters observable in the 

 young assume magnified importance in adult individuals, and from 

 such considerations I regard £. proematurus as distinct from, though 

 closely allied to, B. clavatus. 



VIII. — On the Eelations between the Skiddaw Slates and 

 THE Gkeen Slates and Porphybies op the Lake-distkict.'- 



By Henry Alleyne Nicholson, D.Sc, M.B., F.G.S. 



IN the former portion of this paper, the upper or south-eastern 

 boundary of the Skiddaw Slates, in their main area, had been traced 

 from Troutbeck, on the N.E., as far as the head of Buttermere, on 

 the S.W. From this point (i.e. the north-western end of Honister 

 Crag), the Skiddaw Slates can be traced for a very short distance 

 across Warnscales Bottom, They are still overlaid by the felspathic 

 trap and succeeding band of slates and breccias, which together com- 

 pose Fleetwith Pike and the S.E. end of Honister Crag, and the rela- 

 tions between the two formations are the same as in the Gatescarth 

 Valley. When however the pass of Scarf Gap on the south-west 

 of Warnscales is reached, the Skiddaw Slates have disappeared and 

 the base of the Green Slate Series now rests upon a great mass of 

 intrusive felstone -porphyry (here almost a true syenite) which forms 

 High Crag and High Stile. Though the Skiddaw Slates are absent 

 here, it is interesting to observe that the stratification of the Green 

 Slate Series can be particularly well made out in this region. The 

 rugged hills to the S.E. of Scarf Gap are occujDied by a prolongation 

 of the great slaty band of Honister, but the beds have now to a great 

 extent lost their former character, and have assumed very much the 

 mineral aspect of trap, from which however they are easily dis- 

 tinguished by the fact that the bedding, in spite of a rough but well 

 marked cleavage, is unusually distinct. The strata are excellently 



^ Continued from the March Number, p. 108 



