Uugesiella heutzi (Girakd). 



363 



Color in life; sexual dimorpliism. 



The flrst Impression one gains on seeing- a live female and male 

 together is of the diiference in color. The male looks almost black, 

 while the female is of a light brownish-grey color. When examined 

 more carefully the male shows a number of long bristles offirered 

 color on the back of his abdomen. The female has no such bristles 

 and the hair covering her abdomen is of the same color as that on 

 her leg-s. Her cephalothorax is considerably lighter than her ab- 

 domen and faint stripes of a similar color appear on the patellas, 

 tibias. metatarsi and tarsi. especially of the four front legs. The 

 color of the ventral surface of body and legs is in both sexes a 

 uniform black with the exception of the mandibles, maxillae and 

 lips which are of a fire-red color. The relative length of the legs 

 is in the male considerably greater than in the female and the legs 

 are thinner. The behaviour of the mature male in captivity 

 also differs from that of the female. He is much more nervous and 

 agile, but apparently less inclined to fight, scarcely ever assuming 

 the threatening- attitude ot the female. The role of the so-called 

 secondary sexual characters of the male, represented in this species 

 by two hooks at the end of the first tibiae, will be explained 

 farther on. 



Measurements. Female. The size of the female varies 

 greatly according- to age and nourishment. The following are the 

 measurements (in millimeters) obtained from a rather small but 

 already mature specimen. 



Total length 38,0 ; Cephalothorax, length 15, width 14,6. Distance 

 from dorsal groove to the edge of the clypeus 10,3. The grove is 

 deep, semi-circular, procurve. 



Legs Femur Pat.+ Tibia Metatarsus Tarsus Total 



The arrangementof thespines on the legs is apparently irregulär. 

 They are present only on the tibiae and metatarsi and are more 



