SALTER EURYPTERUS. 85 



On the general characters of the species here described, it is to 



be observed, first, that von Meyer evidently thinks E. Scouleri should 



be regarded as a new type, distinct from Eurypteras, and that 



Scouler's old name, Eidothea, should be restored. Its great size (fully 



1^ foot long), round convex carapace, the processes between the 



eyes (to which might be added their approximate position), and the 



large sculpturing seem to him sufficient to distinguish it. These are 



certainly good characters ; and, if we only knew more of the species 



of the genus, I should be disposed to unite in this opinion. But very 



few of the known species show enough to decide that ornamentation, 



or a slightly different position of the eyes, is accompanied by positive 



characters in the other parts, so as to warrant the distinction. I 



should say the same of his proposed genus AdelojpJithalmus ; for 



scarcely enough is left of the carapace to prove that it had no eyes, 



on which character the genus is founded. Artliropleura is probably 



distinct ; but as the known specimens have neither a whole carapace, 



nor eyes, nor appendages, it would be premature to separate it gene- 



rically. 



ElJRYPTERTJS (ArTHROPLETJRA ?) MAMMATUS, Sp. nOV. FigS. 1-7. 



I have fragments of the head, of the lateral portions of the body- 

 segments, and parts nearer to the tail, but not of the central surface 

 of the carapace, of the eyes, nor of the appendages of this species. 



The first fragment occurred to the Collectors of the Geological 

 Survey, when they were breaking the rubbish of the mine-tip from 

 Pendleton Colliery, Manchester. Others were obtained afterwards by 

 Messrs. Gibbs and Rhind ; and the exact bed proves to be the 

 " Ferny Metal," under the " Big Coal " or " Earns Mine." 



In this bed many plants are found, viz., 



Lepidodendron obovatum. 



Sternbergii. 



elegans. 



Neuropteris Loshii. 

 heterophylla. 



Neuropteris gigantea. 

 Cyclopteris flabelliformis. 

 Sphenopteris obtusiloba. 

 latifolia, &c. 



The bed lies rather high in the " middle coal " series. 



The lateral portions (fig. 1) of the head of this large Crustacean, 

 which must have been at least 8 or 9 inches broad, show a strongly 

 arched border, running out into a short, acuminate, broad spine, 

 into which a strong, curved, sharpish ridge runs from about the 

 upper central portion of the head (probably from the eye itself). 

 The space outside and above this ridge is flat, and is covered with 

 prominent squamse ; beneath it the surface is tolerably smooth and 

 concave, until near the hinder border, at a short distance within 

 which at least six (and probably more) large, mammillated, tuber- 

 cular spines are ranged in a tolerably even line. They are directed 

 backwards, and are full a third of an inch in length, and as much 

 in diameter, at the swollen base. Another portion of the head 

 (fig. 2) shows large and small tubercles instead of squamae. Then we 

 have a fragment (fig. 3) which I suppose to be the hinder margin of 

 the head, with the first body-segment, showing one or two of the 



