EURYPTERUS SHALES OF THE SHAWANGUNK MOUNTAINS 2>°7 



Eurypterus ? cicerops nov. 



Plate 5, figure 10 



This diminutive head shield is remarkable for the extraordinary 

 development of the compound eye lobes which are anterior and very 

 prominent and though the shield has a diameter of only 4.5 mm, 

 the ocellar mound is fully developed. So unusual is the aspect of 

 this specimen that it can not be assigned to any of the other species 

 here noted, and though entirely immature, it is given a distinctive 

 designation. 



Eurypterus ? cestrotus nov. 



Plate 3, figures 8-10 



Of this species we have only enough to satisfactorily establish 

 its difference from other forms — the two specimens here illustrated. 

 Both show the peculiarly ornamented frontal border of the cepha- 

 lon which carries a row of denticulations. One of these specimens 

 conveys a satisfactory idea of the form of the body, and presents 

 the ventral aspect but there is some uncertainty in regard to the 

 number of segments and though evidences of four pairs of legs are 

 present the structure of these is not apparent. The head shown 

 in figure 10 indicates that the compound eyes are large and very 

 far forward. It is entirely probable that when this species becomes 

 better known it will have to be excluded from the- genus Eurypterus. 



Genus hughmilleria 



This genus was established by C. J. Sarle 1 on specimens obtained 

 from the Eurypterus-bearing Pittsford shales lying at the base of 

 the Salina group in Monroe county, New York. 



Hughmilleria has been represented heretofore only by the type 

 species H. s o c i a 1 i s , and its var. r o b u s t a . The critical 

 structural difference between this genus and its close allies Euryp- 

 terus and Pterygotus is the existence of chelate preoral append- 

 ages, much larger than in Eurypterus (E. f ischeri Eichwald) 

 very much shorter and smaller than in Pterygotus, but with the 

 marginal eyes of the latter genus. The form of the animal is 

 slender and terete with no marked abdominal contraction while the 

 head has an elongate rounded subtriangular outline which is quite 

 characteristic. The species here assigned to the genus Hughmilleria 

 has been so treated on the basis of its form and the shape and struc- 

 ture of the head ; the chelate appendages have not been found and 



*A new Eurypterid Fauna from the Base of the Salina of Western New York. N. Y. State 

 Paleontol. Rep't 1902, 1903. p. 1080. 



