384 CAROLINE BURLING THOMPSON. 



the fertile, or reproductive type having a small head with a 

 larger brain, the "small-headed" nymph of Grassi (1896-97); 

 the sterile, or soldier type, with larger head and smaller brain, 

 the "large-headed" nymph of Grassi. The number of antennal 

 segments in these older nymphs is still nine, although the third 

 segment is deeply grooved and subdivided into two parts. The 

 increase in the number of antennal segments is therefore slightly 

 slower than in the genus Reticulitermes, the "small-headed" and 

 "large-headed" nymphs of Reliculitermes, 2 mm. in length, having 

 twelve clearly defined antennal segments. 



Termopsis angusticollis Walker. Termopsis angusticollis pro- 

 duces the largest egg of any American termite. In form, the 

 eggs are long, slender, and reniform, slightly larger at the future 

 head end, and sometimes with surface markings (Fig. I, a). Both 

 in the living eggs and after fixation, and the eggs shrink very 

 little in Gilson's Fluid, two fairly distinct sizes of eggs may 

 be observed. The smallest are about 1.3 mm. long, the largest 

 range from 1.5-1.7 mm. These size differences are independent 

 of embryonic growth, since a large and a small egg may be in 

 the same phase of development. I am unable to state what 

 types of nymphs may hatch from the different sized eggs, for 

 after searching repeatedly in many colonies in Pacific Grove, 

 Cal., I do not feel sure that I have seen the newly hatched 

 nymphs. The smallest nymphs that I have found are 2.2 and 

 2.5 mm. long, with eleven and twelve antennal segments. These 

 may be the newly hatched forms, but their size in relation to 

 the egg, their activity, for newly hatched nymphs are usually 

 sluggish, as well as the eleven or twelve antennal segments, 

 inclines me to believe that they have been hatched for a short 

 time. In one embryo with well formed appendages nine 

 segments could be distinguished in the antennae. I am 

 therefore unable to make any definite statement regarding 

 the body length and the number of antennal segments of the 

 newly hatched nymphs of Termopsis angusticollis, although 

 from the size of the egg I should expect the nymphs to measure 

 about 1.6-1.9 mm. in length, and the number of antennal seg- 

 ments to be like that of the other Protermitidse, Calotermes 

 and Cryptotermes, namely, nine, with the third segment either 

 entire or subdivided. 



