62 The Gra^pedosomatidBe of North America. 



Another result of this condition of things is that the joints and 

 sutures are not so evident, and the distinction between the men- 

 tum and promentum appears to be obliterated. The mentum, as 

 well as the surrounding parts, is merely membranous, and no 

 flexibility would be added if the usual joint were present. 



TRICHOPETAI^UM Harger, 1872 (emended). 

 Am. Jouru. Sci. and Arts IV, 117. 



Oraspedoi^oma, Latzel and Bollman ; Scoterpes Bollman. 



Eyes moderately developed, of several (J 0-14) ocelli arranged lunately in 

 two or three curved rows. 



Antennfe rather short, clavate; third and fifth joints subequal in length. 



Mandibles with nine pectinate lamellae. 



Promentum present, triangular. 



Segments with moderately prominent, shoulder-like carinse. 



Male legs with first joint not hispid. 



Third, fourth, fifth and sixth legs of males strongly crassate. 



Ninth pair of legs of male two-jointed, the distal joint broadly clavate, un- 

 armed except that on the outer face of the last joint, near the aj)ex is a small, 

 blunt, chitinized knob, possibly the rudiment of a claAV. 



Tenth and eleventh legs of male with the coxae perforate. 



Genitalia of male consisting of a single pair of decurved structures hirsute 

 antero-basally and with plumose-laciniate processes posteriorly. 



Segments of adult 28. 



Distribution : Northeastern North America. 



The original description of this genus reads as follows : 



"Sterna not closely united with scuta ; third and fifth joints of the antennae 

 elongated ; scuta furnished with bristles ; no lateral pores ; eyes present. ' ' 



It will be seen that these characters, with the exception of 

 " eyes present," are applicable to all Craspedosomatidas. Indeed, 

 it is probable that the genus Trichopetalum would not have been 

 erected had not its author been misled by Gervais' figure into the 

 supposition that in Craspedosoma the pedigerous laminae are co- 

 alesced. But notwithstanding that the generic characters origi- 

 nally alleged are entirely insulTlcient, there can be no doubt that 

 in Harger's T7'ichopetatum lunatum was discovered a generic 

 type, and we have preferred to retain the name, supplying other 

 characters for the generic diagnosis. 



In comparisoa with this genus'the anterior legs of the males of 

 Zygonopus are remarkable for their slenderness, only the sixth 

 legs being comparable in size with the corresponding ones of 

 Trichopetalum. 



