PHALANGEiE OF THE UNITED STATES. 17 



must be cut open before the organ itself will come into 

 view. In the genus Phalangium the penis is made up of 

 two portions, the body and a second piece, generally 

 very small, and ending in a sharp point. The body of 

 the male organ is traversed by the continuation of the 

 spermatic duct or the ductus ejaculatorius, which opens 

 at or near the distal end of the smaller article. In the 

 latter part of summer many male Harvest-men may be 

 found, in which the organ, with its sheath massed about 

 its base, is extruded from the body. 



Occupying a corresponding position with the last, in 

 the female is a long, firm, almost cartilaginous, more or 

 less annulated tube, the ovipositor, into the base of which 

 opens the oviduct. This, like the penis, is capable- of 

 extrusion, and is provided with a sheath. 



Suborder PHALANGES. 



Respiration trachean. Thorax not distinctly articu- 

 lated. Mandibles very conspicuous, free, terminated by 

 a didactyle forceps. Abdomen annulate ; no metamor- 

 phosis. 



Family PHALANGID^. 



Abdomen distinct superiorly. Coxoe of posterior pair 

 of feet not more developed than the others, and radiating 

 at about the same angle as the others. Tarsi multiartic- 

 ulate. 



Genus I. PHALANGIUM Linn. 

 Palpi without spines. Eyes two on a tubercle. 



COMMUNICATIONS ESSEX INSTITUTE, VOL. VI. 3 JULY, 1868. 



