280 
Psyche 
[December 
The problem that results from this dimorphism is that of properly 
pairing the male and female of the same species. With the rare ex- 
ception of finding two spiders in copula or, in some Araneidae for 
example, finding the apical tip of the embolus broken off inside the 
seminal receptacle of the female, this problem must be solved indirect- 
ly. This is the point at which a taxonomist’s intuition or reason is 
required. In addition to the comparison of the two adult sexes the 
use of the immature forms may now come in use. Many araneologists 
consider pre-adult forms (i.e. those lacking male palpi or epigyna) to 
be taxonomically useless. But the external morphology of the im- 
matures will be less affected by the strong sexual dimorphism found in 
many adults and therefore exhibit the more stable characters in the 
species. 
In a recent article (Unzicker, 1965) two new species of Myrme- 
cotypus were described. Each one was described from a single speci- 
men: M. rettenmeyeri Unzicker from a male, and M. discreta 
Fig. 1. Lateral view of Myrmceotypus rettenmeyeri Unzicker. 
Fig. 2. Lateral view of Camponotus serieeiventris (Guerin). 
