THE EURYPTERIDA OF NEW YORK 267 
extremity of the first unpaired lobe are observable. The appendage extends 
beyond the middle of the second sternite, but the specimen is prob- 
ably stretched. In Hall’s type, which is clearly contracted in the preab- 
domen, it extends to the middle of the-fourth sternite. | 
No surface ornamentation has been observed except linear rows of 
high, circular scales on the proximal segments of the last two pairs of limbs. 
Measurements of type: : millimeters 
Length of carapace... 6... kee eee ees 57-5 
Width of carapace... 0... ccc cece eee cece ease ee eeees 70 
Length of eyes... 0... ee tee een een . 13 
Length of metastoma......... cee cece eee eee 32 + 
Anteroposterior length of coxa of last leg................ 43 
Length of swimming leg beyond carapace................ 125 
Length of preabdomen......... 0.0.0.0... eee eee 68 + 
‘Width of preabdomen...0.....00..00.. cece eueee. _— 74 
Length of tergite.. 2.0... . ee eee 15+ 
Length of operculum about..........00...0 000.000.0000. 25 
Length of opercular appendage about..................4. | 52 
Length of first postabdominal segment unknown; width of 
same about. 2... 6 cee cece ee eee e ees 52.5 
. Some measurements complementary to the preceding are afforded by 
the Litchfield specimen. : 
The metastoma is 30.4 mm long; 16.5 mm wide ad maxiinum and 
It mm at the posterior end. | 
The coxa of the last limb is 35.7 mm long on the inner side and 
22.4 on the posterior. The swimming leg measures 128.7 mm; its eighth 
segment is so much contracted that the original length was about 130 mm, 
The preabdomen is 53 mm long and 54 mm wide. The postabdomen 
measures 90 mm in length; it is 53 mm wide atits anterior end and 28 
mm at its posterior end. The first sternite is 12.5 mm long, the last 109.5 
mm. Of the telson 44 mm are preserved; its initial width is 15.5 mm. 
