1875.] 507 IMles. 



ent by potash, and shows the sac attached by its base at a, as in Fig. 

 1, and the tube b much lengthened, passing twice round the inside 

 of the bulb, and opening in the penis at c. In the various species 

 of Linyphia and Erigone the complication of the palpal organ is still 

 greater, but the internal structure is the same. The only variation 

 I have seen is in Linyphia autumnalis, and an allied undescribed 

 species, where the duct has a spherical enlargement midway between 

 the sac and the penis. 



The Physical Features of the State of Massachusetts. 

 By W. H. Niles. 



The geographical position of the State of Massachusetts insepar- 

 ably unites her territory to the Appalachian mountain system, and 

 gives rise to the most conspicuous features of her hills and moun- 

 tains. Massachusetts presents four distinct physical regions, in two 

 belts of highlands and two of lowlands, which cross her territory 

 from the northern boundary to the southern. The western region is 

 that part of the Green Mountain chain which is within the State, 

 and it embraces a large portion of the Taconic and Hoosac ranges. 

 East of this lies the Connecticut Valley region. This is succeeded 

 by a broad belt of uplands, forming a central region of distinct phys- 

 ical features, but Avhich has no recognized name by which it may be 

 designated. The fourth is that extent of relatively low land adjoin- 

 ing the coast, which is a part of what has been called the "Atlantic 

 Plain." 



The laws of elevation discernible in a comparative study of these 

 regions are but a part of the system embodied in the structure of the 

 Appalachians. Throughout that portion of this mountain system, 

 which lies east of the valley of the Hudson and south of the highest 

 of the Green and of the White Mountains, the ranges increase in 

 height as they succeed each other toward the west, and both high- 

 lands and lowlands gradually rise towards the north. As Massachu- 

 setts is a part of this region, her surface is elevated in accordance with 

 both of these more general laws. Thus the western belt of highlands 

 exceeds the eastern in elevation, and the Taconic Mountains average 

 higher than the Hoosac range ; and hence the northern part of each 

 of the four physical regions is higher than its southern part. Thus 

 the mountain-forming forces, increasing the elevations toward the 



