110 PIIYLLOPODA. 



illustrious author of the Syst. Naturae. Entire specimens are only 

 found in the Quarry of Alum-slate of Andrarum in Scania, (that 

 figured by Mons. Desmarest is upwards of two inches in length) j 

 fragments, on the contrary, are abundant over the whole of Westro- 

 gothland. I must not neglect to point out a semicircular inscription 

 at the side of the head, Mr. Wallenberg says, almost as in the B. 

 Tessini. 



For the benefit of Geologists who have not seen Mr. Wallenberg's 

 Essay on these animals, nor the transcript in the Journal de Phy- 

 sique for July 1820, nor Mons. Desmarest's work, I have added 

 figures of the other Eyeless Trilobites of Sweden, viz. Paradoxides 

 Scaraboides, PI. 5, f. 5, and Paradoxides Gibbosus, PI. 5, f. 4,. . both 

 of these appear to be very common in the Aluminous formation, 

 and particularly in the included swine-stone. 



Ogygia, 



This Genus, so named from appearing to possess the greatest an- 

 tiquity of all the Fossils of the Transition formation, like the former, 

 is extremely local, and has never been observed but in the roofing 

 slate of Angers, in France. Whether the two species met with, are 

 really such, or only indicate a sexual difference, is doubtful; I incline 

 to the latter opinion, and consider O. Desmaresti, PI. 6, f. 2, as the 

 male, O. Guettardi as the female, which is rendered more probable 

 by Mons. Desmarest having observed in a full grown specimen, an 

 oval pad on each side of the tail, much thicker than the rest of the 

 body, and hence corresponding, in some measure, with the oviferous 

 conceptacles in Apus. 



This Genus differs from Bucephalithus, in the members being 

 apparently connected together, or perhaps covered by a membra- 

 neous expansion. There is a division in front between the Horns, 

 and another flexuose articulation at the side of the Head, as in the 

 former Genus, the Horns being extended backwards along the sides 

 of the body, from which they are, nevertheless, quite separate... 

 What Desmarest considers as oculiform protuberances, I consider, 

 as the places of the mandibles. 



Ogygia Guettardi, PI. 6, f. 1, rarely found entire in the roofing 

 slate near Angers, its fragments, on the contrary, are very common ; 

 varies in size from about 4 inches to near a foot in length ! 



Ogygia Desmaresti, found with the former, I consider as the 

 male; it is altogether much broader in proportion, and the Horns 

 very broad but rather shorter and more si)reading,. . probably attains 

 the length of near 1 5 inches ! but haa not been met v, ith entire. 



