40 PROCEEDINGS OF THE ACADEMY OF [Jan., 



in front of each; outer or posterior piece narrowed above, its top 

 rounded and a little bent, bearing a long bristle, at base also one or 

 several long bristles. 



Segments 47-57. Length, 36 mm.; width, 1.9 mm. 



Remarks. — The specimens studied include three adults, two males 

 and a female, and several immature individuals. The measurements 

 given are from the largest individual, a male. 

 Polydesmus sp. 



Several young individuals of a species of this genus are in the col- 

 lection. They are of the stage possessing only twelve segments, and 

 thus too young for determination. 



