BIIITISH FOSSILS. 



Decade VIIL Plate VI. 



ASFIDORHYNCHUS FISHERI. 



[Genus ASPIDORI/TNCHUS. Agassiz. (Sub-kingdom Vertebrate. Class Pisces. 

 Order G oniolepidoti. Family Sauroidei. Sub-family Sauroidei homocerci. 1st Group. 

 Tail forked.) Body much elongated ; upper jaw produced in the form of a beak; pectoral 

 and ventral fins rounded ; dorsal fin far back and opposite the middle part of the anal fin ; 

 tail forked ; scales higher than wide, especially in the middle part of the body ; teeth 

 extending in the upper jaw beyond the point of the lower jaw.]* 



Aspidorhynchus Fisheri. Sp. Nov. 



Description. — Three species only of this genus are figured and 

 described by Professor Agassiz m the " Poissons Fossiles.'' In addi- 

 tion to these, six others are named and briefly noticed. The 

 characters of all these are well known to me, with the exception 

 of Aspidorhynchus Wcdchneri, a fossil of the lias of the Oberlacd 

 Badois ; of which 1 have never seen a fragment. As no informa- 

 tion is given with respect to this fish, and as it is not likely that 

 it can be identical with a Purbeck species, it will be omitted in 

 considering the subject before us. Of the eight remaining species, 

 five are from the oolites of Solenliofen and Kelheim ; one from the 

 lias of Whitby ; one from the Oxford clay of Christian Malford ; and 

 one from Barra do J ardim in Brazil, from a stratum probably about 

 the age of the Green Sand. The subject of this article, a fish of the 

 Purbeck beds, difiers in many respects from all the species alluded 

 to by Agassiz, and possesses individual features so clear and distinc- 

 tive, that it would be superfluous to enter at length into a descrip- 

 tion of the agreements and discrepancies existing between it and the 

 other members of the genus. A simple enumeration of the characters 

 of the species will suffice to establish it without risk of confusion. 

 In form a^d proportions, it holds an intermediate position between 

 Aspidorhynchus acutirostris and Aspidorhynchus mcindibularis, 



[viii. vi.] 



Poiss. Foss. vol. ii. page 14. 



