176 University of California Publications. [ ZooLoGy 
& Pigment knob on right side; abdomen symmetrical; ante- 
rior antennae as in female as regards armature; grasping 
antenna on left side; first joint of inner ramus of second foot 
with hooks only on right side; third and fourth feet as in female. 
Coloration: As in P. abdominalis. 
Length: Both sexes, 1-2 mm. 
Occurrence: More abundant than P. abdominalis, but males 
are rare. 
Brady, 1883, p. 47, considers that P. gracilis Claus is an 
immature form of P. abdominalis Claus, but Giesbrecht, 1892, 
does not favor this view, and the San Diego specimens of P. gra- 
cilis present such differences when compared with P. abdominalis 
that there can be no doubt of the distinctness of the species. The 
forms represented by P. gracilis are without doubt mature, since 
females are often found with attached spermatophores. 
3. Pleuromamma xiphias Giesbrecht. 
Pleuromma sxiphias Giesbrecht, 1889, p. 6; 1892, pp. 347, 367, 
pl. 32, fig. 14; pl. 33, figs. 42, 45, 50. 
Pleuromamma wxiphias Giesbrecht, 1898, p. 110. 
Fig. 34.—Pleuromamma sxiphias. (a) Female, lateral, X18. (b) Head 
of female, lateral, X48. (c) Second basal, and proximal 
joints of rami of second foot, x48. 
