WELLBORN : FOSSIL FISH FOUND IN THE MILLSTONE GRITS. 397 
Branchial Region is shown, but the five calcified gill arches 
are not well marked. 
Fin-spines. The pectoral is well shown, being broad, robust, 
somewhat laterally compressed, and shows a faint groove and ridge 
parallel with the anterior border, disappearing distally. The spine 
being displaced upwards and backw^ards into the body, the fin is not 
shown. 
Ventral. — The basal part of this spine is shown, and there 
also appears to be a faint indication of the basal part of its fin ? 
The spine is situated at a point " about one-third nearer the 
pectoral than the anal spine." 
Anal.— On\y the basal part of this spine is shown. 
Dorsal. — Well shown at a point slightly behind the anal 
spine ; it is slightly less than half the size of the pectoral spine, is 
not so much laterally compressed, is somewhat tumid proximally, 
and shows a well marked groove and ridge parallel with its 
anterior border. No fin is shown, the spine being compressed 
downwards and backwards into the body. 
Determination of species seems to rest between A. Wardi Egerton 
and A. nitadns A. Woodward, and I refer the specimen with 
some hesitation to the former, considering the character and 
position of the ventral fin. 
3. Acanthodes sp. ? 
Mr. Aitken mentions part of the body and scales of this 
genus, the species being doubtful. 
4. Acanthodes sp. ? 
The specimen shows two fin-spines — probably the dorsal and 
pectoral ; also patches of scales which are very minute. The 
determination of species is impossible, the specimen having suffered 
so much from erosion. 
Sub-class : Teleostomi. 
Order I. : Crossopterygii. 
Sub-order : Rhipidistia. 
Family : Rhizodontidw. 
Genus : Strepsodus Young. 
