THE EURYPTERIDA OF NEW YORK 29 
Besides the scales and spines the integument of the eurypterids was 
also in many parts covered with fine hairs as in Limulus, especially on 
the lips and legs. These have been observed and photographed by Holm 
in E. fischeri. 
Pores of doublures. Schmidt [loc. cit. p. 67] has observed that in 
Pterygotus the posterior third of the dorsal thoracic segments is provided | 
with a separate interior lamella or doublure (‘‘ Umschlag’’) perforated 
by numerous fine tubes especially abundant toward the posterior and 
lateral margins. In Eurypterus this doublure is present but imperforate. 
A slightly weathered specimen of Pterygotus buffaloensis 
very beautifully exhibits this interesting feature not only verifying Schmuidt’s 
observations but also allowing some amplification of them. In this speci- 
men, the pores are distributed over the whole lamella, but are most closely 
arranged and most distinct in a belt occupying the posterior third of the 
lamella except for the hindmost millimeter which is entirely imperforate. 
Where fully exposed, they appear as sharp black lines, about 14 millimeters 
long, passing from below and posteriorly, obliquely upward and forward. 
At the posterior margin of the belt they stand more vertical but they rapidly 
bend forward and increase in obliquity of direction toward the anterior mar-' 
gin of the belt. They are most distinct on the tergites, but have been 
seen on the sternites in a’ similarly situated, though narrower belt, 
corresponding to the smaller width of the doublure. Similar belts of 
pores are visible on the posterior thirds of the broad doublures of both 
the dorsal and ventral sides of the abdominal segments, and on the narrow 
doublure of the posterior margin of the head. 
The weathered head of the same specimen also exhibits anastomos- 
ing lines near the center and a ring of several rows of black points and 
lines which seem to indicate either the presence of similar pores or of a 
system of pits. 7 
- Another row of pits which seem to have been pores, is also seen just 
inside the flexure of the head shield into the doublure. These would seem 
to correspond to the row of ‘‘Punkte’’ observed by Holm in Eurypterus 
