270 Proceedings of the Royal Physical Society, 



shaped space, the lateral angles of which were continuous 

 with fissures running outwards between the eyelids. The 

 floor of this space was of a reddish colour, and appeared to 

 be formed by mucous membrane, but there were no indica- 

 tions of an eye. 



Plate xlvii., fig. 3, of Ahlfeld's Misshildungen des Ifenschen, 

 shows a specimen in which the external appearances were 

 very similar to those in this case. Unfortunately the brain 

 was very soft, so that its exact condition could not be 

 accurately determined ; but there was evidently only one 

 cerebral hemisphere, and no indications of a longitudinal 

 fissure. We could find no traces of the olfactory nerve, and 

 there were only a single optic nerve and foramen, but all the 

 other cranial nerves were present. In the dissection of this 

 specimen special attention was directed to the condition of 

 the bones of the skull and the formation of the orbital and 

 nasal cavities. A few of the bones were apparently absent, 

 some considerably altered in shape, and even those of normal 

 configuration were smaller than usual. 



The occipital bone consisted of four pieces — a basi-occipital, 

 two ex-occipitals, and a supra- occipital ; the latter was in- 

 clined more nearly vertical than usual. The squamoso- 

 zygomatic and petromastoid parts of the temporal bone were 

 firmly united together; they were very small, and rather 

 irregular in shape. The parietals were normal. 



The frontal consisted of a single piece, and there were no 

 indications of a suture between its two halves. It had two 

 distinct orbital plates, but the ethmoidal fissure between 

 them was very narrow. 



The changes in the sphenoid bone were almost entirely 

 confined to its anterior part or pre-sphenoid. The body of 

 the post-sphenoid was well developed. The right great wing 

 was united with it by bone, but the left one was still separated 

 from it by cartilage. The internal pterygoids were united 

 with the great wings. There were no indications of the 

 body of the pre-sphenoid. The lesser wings were ossified, 

 and between them was placed the single optic foramen, which 

 was bounded by the dura mater. 



