160 PROCEEDINGS OF THE NATIONAL MUSEUM VOL. 97 
Tanystylidae, and Colossendeidae, have ovigers in both sexes. Most 
of these families are also characterized by the presence of both cheli- 
fores and palpi in the adults, although the chelifores are reduced in the 
Tanystylidae and usually absent in adult Colossendeidae. The 
-second group, comprising the Phoxichilidiidae, Endeidae, and 
Pycnogonidae, have ovigers only in the male and lack palpi, with 
the exception of rudimentary knoblike growths in some Phoxichili- 
diidae. - Chelifores are also lacking in the Endeidae and Pycnogonidae. 
Midway between these groups is the family Pallenidae. Ovigers are 
present in both sexes in this family, chelifores are present and often 
well developed, but the palpi are greatly reduced or entirely lacking. 
In this family is included the genus Pallenopsis, which resembles the 
phoxichilidiid genus Anoplodactylus in the possession of tubular 
femoral cement glands in the male and in the structure of the cephalic 
segment. Pallenopsis has in fact been included in the Phoxichilidiidae 
by several writers, notably Calman and Gordon. 
Fentanymp hop 
Ficure 4.—Diagram of the families of Pycnogonida. The fractions indicate genera 
and species. 
