878 Reports and Proceedings — Zoological Society of London. 



granite, in the Gannister or Mountain-Mine seam of the Eossendale 

 district, at Old Meadows Pit, near Bacup, Lancashire, had led the 

 author to call attention to the occasional occurrence of similar 

 boulders in various parts of Lancashire and Yorkshire. Suck 

 boulders were always isolated, and sometimes imbedded in the seam, 

 sometimes in its upper surface. They were always waterworn and 

 rounded, and were composed, so far as had been observed, of granite, 

 gneiss or quartzite foreign to the district. 



After considering the various suggestions that had been made as 

 to the means by which such boulders had found their way into the 

 coal, the author gave the preference to the action of floating-ice, 

 both because the presence of fragments from a distance would thus- 

 be more readily explained, and because ice-scratched rocks have been, 

 found in situ in the Millstone Grit within three miles of the place 

 whence the boulder mentioned was obtained. 



The next Meeting of the Society will be held on Wednesday, 9th 

 November. 



III. — Zoological Society of London". 



May 17th, 1887.— Prof. W. H. Flower, LL.D., F.E.S., President, 

 in the Chair. — The following communications were read : — 



1. " On the Presence of a Canal System, evidently Sensory, in the 

 Shields of Pteraspidian Fishes." By A. Smith Woodward, F.Z.S. 



A broken specimen of Pteraspis Crouchii in the British Museum 

 adds an interesting fact to our knowledge of the structure of the 

 shield in the Pteraspidian fishes. In his well-known monograph 

 on this ancient group, Prof. Eay Lankester described a number of 

 pits or depressions arranged in rows upon the external surface 

 of certain well-preserved examples, and considered that they were 

 connected with the "lateral line" system of the fish, probably 

 lodging the sensory organs situated in an enveloping soft integu- 

 ment. The same feature was again described in Holaspis in 1873 

 (Geol. Mag. Vol. X. p. 243, PI. X.) It now appears that these 

 curious depressions are really the openings of a canal system, 

 traversing the middle layer of the shield, and quite comparable to 

 the canals of the lateral line in many ganoids and teleosteans. The 

 branches have the remarkable "feather-barb " arrangement, so well 

 seen in the living Pleuronectidge. 



2. " Note on the ' Lateral Line ' of Squaloraja." By A. Smith 

 Woodward, F.Z.S. 



In his description of the genus Squaloraja, recently published, the 

 author had failed to recognise traces of the lateral line. He now 

 showed that these canals were supported by numerous minute, in- 

 complete, calcified rings, exactly similar to those well known in 

 recent and fossil Chim^roids. The fact probably implied that the 

 sensory organs were placed in open grooves, and thus added one 

 more feature to those already noted as connecting the old Liassic- 

 Selachian with the Holocephala. 



