380 Reports and Proceedings — Geological Society of London. 



amphibole with apatite, magnetite, pyrite, olivine, augite, chlorite, 

 and calcite ; an analysis of this variety is given; (2) amphibolite, 

 ■with larger hornblende crystals separated by tine-grained amphibole ; 

 (3) actinolite rock, mainly made up of actinolite, but bearing also 

 zoisite, sphene, and sulphides ; (4) zoisite-amphibolite, made up of 

 poecilitic hornblende enclosed in a granular matrix which is white 

 with zoisite; and (5) 'quartz-mica diorite,' containing quartz and 

 felspar. The last variety is conceived to be a mixed rock, formed by 

 the absorption of the amphibolite hy an acid magma ; an analysis of 

 one of the most acid types is given. The Ordovician sediments are 

 converted into hornfels at the contact with the igneoiis rock, and this 

 type of rock has resisted the dynamic metamorphism which occurs 

 elsewhere in the district. The Greystones rock shows a transforma- 

 tion from peridotite into amphibolite, but with a greater development 

 of talc. Olivine and rarely mica are present in the original rock. 



2. "On the occurrence of Footprints in the Lower Sandstones of 

 the Exeter district." By Principal Arthur William Clayden, M.A., 

 F.G.S. 



Suitable exposures in the ' Lower Sandstones ' of the Geological 

 Survey map are very rare. Dr. Shapter has recorded ' claw-like 

 footmarks,' etc., from a locality about half a mile north-east of 

 Broadclyst. Another quarry has been recently reopened here for 

 building stone ; and, on a search being made, slabs with footprints 

 were found by the author and his students. Later, a slab with 

 a track containing thirty pairs of footprints was found. In all, five 

 specimens have been secured ; and three of the sets of prints may 

 have been made by the same individual, one with fore and hind 

 feet aboiit the same size and bearing about the same weight. The 

 two other sets of prints were made by smaller and different 

 individuals. In one case the prints of the manus are slight, and 

 those of the pes heavj-, although the hind and fore feet were of about 

 the same size. There is no trace of the tail being dragged. In 

 the other the animal had all the characters of the last, except that the 

 digits 5 and 2 were nearly equal. This track also shows that the 

 animal sometimes threw nearly all its Aveight on the right side and 

 sometimes on the left. In no case is there anything to suggest 

 either claws, a sole to the foot, or a fifth digit. They are least 

 unlike Cheirotheroid prints, but differ from them in the absence of 

 a divergent digit. The specimens have been presented to the Exeter 

 Museum. 



3. •' The Basic Intrusion of Bartestree, near Hereford." By Professor 

 Sidney Hugh Eeynolds, M.A., P.G.S. 



The Bartestree dyke, which has a thickness of about 35 feet, 

 strikes in an east-north-easterly direction through the Old Red 

 Marls and Sandstones, which for a distance of at least 10 feet from 

 the contact are strongly metamorphosed, the marl being converted 

 into a hard purplish-grey rock with yellow patches, while in the 

 sandstone the felspars are recrystallized and the quartz grains corroded. 



The dyke itself is not a single uniform intrusion, but a multiple 

 dyke composed of several allied though differing types of dolerite and 



