PLATE LXVIl. 



Drawing oi the upper surface of the anterior extremity of a specimen of Ipnojis 

 murrayi preserved in spirits, much enlarged. Drawn from the specimen by Mr. 

 Charles Drummond, artist to the Radcliffe Library, Oxford. The two phosphor- 

 escent organs occupy nearly the entire upper surface of the skull, extending 

 from just behind the nasal region to almost the posterior extremity of the cranial 

 cavity. They arc seen through the transparent thin bony upper walls of the 

 skull. Their upturned margins being deeply pigmented show clearly the exact 

 extent of their area. The right organ and its coverings are represented as seen 

 comparatively superficial]}-, the left organ as viewed ^\^th a deep focus of the lens. 

 Hence the cui-ved con\ex orbital area of the skull-roof and its flattened concentrically 

 striate area are seen on the right hand, whilst on the left the hexagonal bodies 

 of which the organ itself is composed are indicated in two places, as seen through 

 the skull-roof. A pair of bony canals traverse the skull surface on either side ot 

 the median septum antero-posteriorly. They transmit the two nasal branches of 

 the fifth nerve, which are seen passing to the nasal capsules, but are mainly 

 occupied ])y large mucous canals wliicli are of a glistening opaque white owing to 

 tlio action of spirit. 



