Mr. F. E. Beddard, F.R.S., read a third of a series of papers 

 on the Anatomy of the Lacertilia, which dealt with points in the 

 vascular system of Gliamceleon and other Lizards. 



A communication from Mr. A. D. Imms, B.Sc, contained notes 

 on the gil]-ra*lcers of Polydon, in which he pointed out that these 

 pi'ocesses in this Fish were setiform structures disposed along 

 both the anterior and posterior edges of the first four branchial 

 arches and along the anterior edge of the fifth arch also. Each 

 gill-raker consisted of a basal portion, which was attached by 

 means of elastic fibres to the cartilage of the branchial arch, and 

 a long, free shaft portion which formed its principal part. The 

 mati'ix of a gill-raker contained numerous lacunar spaces which 

 were connected with one another by means of canaliculi, and in 

 the shaft portion it contained, in addition, a series of anastomosing 

 channels in which lay blood-capillaries and some loose connective- 

 tissue. The mucous membrane covering a branchial arch was 

 prolonged over each gill- raker in the form of a complete investing 

 coat. The gill-rakers of Polydon were exoskeletal structures, 

 and they appeared to be composed of a substance closely allied 

 to osteo-dentine, and their presence on the branchial arches 

 might perhaps be accounted for on the supposition that the 

 ectodeim forming the outer portions of the gill-clefts had migrated 

 on to the inner margins of the bi-a^nchial arches. The food of 

 Polydon consisted of microscopical organisms, and the gill-rakers 

 function as a straining mechanism Avhich eflTectually barred the 

 entry of such particles into the gill- cavities. 



A paper w^as read by Dr. W. G. Ridewood, F.Z.S., on the 

 " Cranial Osteology of the Elojndce and Alhulidce, with Remarks 

 on the Morphology of the Skull in the Lower Teleostean Fishes 

 generally." The paper included a detailed account of the skulls 

 of Elojys sawus, Megcdo2JS cyprinoides, Alhula conorhynclius^ and 

 Bathythrissa dorscdis, together with remai-ks, generalisations, 

 and criticisms of published accounts of the skull-bones of fishes, 

 based mainly irpon an examination of the skulls of 20 species of 

 fishes selected from among the most primitive families of the 

 existing Malacopter3rgii. 



Among other features pointed out by Dr. Ridewood was the 

 fact that in Elops and Albida, although the parietals met in the 

 middle line, the supraoccipital extended forward beneath them to 

 reach, and even to underlie, the frontal bones ; in the former 

 genus and in Megalops the supraoccipital also touched the ali- 

 sphenoid bones. The posterior temporal fosste were so great in 

 Megalojys that they reached the orbitosphenoid bone, and they 

 communicated freely above the brain-case. A careful comparison 

 of the skulls of Bathythrissa and Alhida confirmed the close 

 relationship existing between these genera suggested by Boulenger 

 in 1898. Except that in some few respects the bones were 

 modified in correspondence with a deep-sea habit, the skull of 

 Bathythrissa bore a very close resemblance to that of Albida. 



