158 MR MALCOLM LAURIE ON SOME ETJRYPTERID REMAINS FROM THE 



the segment, and their outer ends are rounded. The median lobe is 7 mm. long and 

 4 mm. wide at its base, and has a pointed angular form not common in this genus. 



Ornamentation of the ordinary kind is not shown on any part of the body, but fine 

 anastomosing veins run over most of the surface. 



Only fragments of the limbs — of no value for descriptive purposes — are preserved. 



The form of the metastoma — slightly distorted — is shown in fig. 1 3. 



In the position of the eyes this form approaches most closely to E. lanceolatus (Salt.), 

 (v. Woodwaed, pi. xxviii. figs. 1-3), but they are much larger in proportion. The form 

 of the telson is somewhat more taper in this than in E. lanceolatus, and resembles most 

 closely the fragments described by Salter as E. linearis* E. linearis, however, is 

 considered by Schmidt! to be a synonym of E. Fischeri, a species very distinct from 

 E. conicus. The form of the genital plate is also different from that of E. lanceolatus, 

 but too little is known of the sexual variations of this structure for it to be of much value. 



Eurypterus cyclophthalmus, n. sp. (PI. III. fig. 15.) 



This species is represented by only one specimen, which shows the greater part of the 

 carapace and portions of all the body segments. The carapace is semicircular in form, 

 12 mm. long and 16 mm. wide at the posterior margin. It is bounded all round by a 

 well marked narrow border (less than 1 mm. in width), and is destitute — as is the whole 

 body — of scale-markings. The eyes are large (3*5 mm.), subcircular, and somewhat 

 widely separated from each other (4*5 mm.). They are somewhat nearer the lateral than 

 the anterior border of the carapace, and rather towards the front. Between the large 

 eyes are a pair of small central eyes, which were probably placed on a prominence. 



The body increases in width to about the 3rd segment, and then decreases rapidly 

 to the 7th, which is conical in form, and more gradually from the 7th to the end of the 

 tail. The first six segments are short, the 7th very long, the 8th not so long as the 7th, 

 and the succeeding ones about the same length as the 8th. The measurements may be 

 tabulated as follows : — 



1st, 



1-8] 



nam. long. 







2nd, . 



2-5 



» 







3rd, . 



2-9 



» 







4th, 



3 



j> 







5th, . 



3 



)> 







6th, . 



33 



» ' 



7 



mm. wide 



7th, . 



4 



» • 



6 



» 



8th, . 



4-9 



» • > 



6 



» 



9th, . 



5 



» • < 



5 



» 



10th, . 



. U? 





4 



» 



11th, . 



» • • 



? 



>> 



12th, . 



. J 





? 



a 



The telson is not preserved, and there are only traces of the swimming feet. 

 * Woodward, pL xxviii. figs. 10-12. t Schmidt, Mem. de I' Acad. Imp. d. 8c. de St. Petersbourg, vol. xxxi. p. 50. 



