Pomona College, Claremont, California 147 



newly emerged young were shell pink and shiny. After emerging 

 from the egg sac they moulted and at three days oi age had a light 

 brown cephalothorax with black eye space, light brown legs and 

 spinnerets and a reddish brown abdomen. The legs, abdomen and 

 spinnerets were covered sparsely with dark hairs. The trapdoor 

 spiderlings were so slow in changing that the moults occurred about 

 a month apart. At the age of one month and three days the young 

 had grown slightly larger, the cephalothorax was light brown with 

 darker brown in the cervical groove. There was a brown line 

 from the black eve space down to the first groove ending. The legs 

 and spinnerets were the same color as before. The abdomen 

 was colored a little darker brown and six light spots were on the 

 middle surface of the abdomen. The spinnerets were shorter than 

 at the three-day stage. At the next moult (two months and six 

 days), the shape and coloring of the spiderlings had changed con- 

 siderably. The cephalothorax had elongated, the color was red 

 brown, the eve space black. The abdomen had become smaller and 

 the spinnerets disappeared from sight. The color of the abdomen 

 was dark reddish brown with numerous Hecks of lighter brown over 

 the surface of the abdomen. The legs and palpi were gray brown. 

 At three months and six days the whole spider had changed from the 

 reddish brown color to the chocolate brown. The cephalothorax 

 was chocolate brown with black eye space. The abdomen had 

 become the shape of the adult's and was a dark chocolate brown 

 with numerous horizontal ridges. The legs were gray brown. At 

 the age oi four months the young had taken all the color of the 

 adult, though their si/e was only one-tenth that of the mature spider. 

 There is in the collection a specimen of Bothriocyrtum of about a 

 year's age. It is three-fourths the size of the adult, and though its 

 sex is not differentiated yet, it has all the adult coloring. From 

 these observations it is concluded that it must take several years 

 for the spider to reach maturity. 



The conclusions reached after the study of these families of 

 spiders may be stated in a few paragraphs: 



1. The young in all cases resemble the adult in shape of body, 

 placing of eyes and in habit. This was true oi the young iusr 

 emerged from the egg sac as well as the older ones. The shape of 



