XYODESMIDA^. 
17 
cles ; last segment with marginal processes inconspicuous ; pores located on 
the under side of the carinse ; sterna of the posterior pair of legs of each seg- 
ment with a long, incurved spine. ........ 
Lateral edge of carinse with a few distinct, rounded tubercles, on the infe_ 
rior face of the largest of which the pores are located : Genus Hypode sinus, 
nov., type H, constrictus Bogota. 
Lateral edge of carinse finely granulate or denticulate, the pore located under 
the most projecting part, but not on a special and distinct tubercle or callus • 
Genus Trachelodesmus (Ptrs.), type Tr. arcticollis (Ptrs.), Caracas. 
In all the genera of this family the sterna are unusually wide, but 
the American forms are further remarkable in that the sterna are 
spined. The absence of such spines characterizes the African sub- 
family Xyodesmini. The Trachelodesmini are characterized by the 
robust body, the short and pointed anterior carinae, the normal pore- 
formula, and the uniform development of the sternal spines, while 
Batodesmini have the body slender, all the carinse narrow and pointed, 
the remarkable pore-formula, and the development of very long 
spines on the sterna of posterior segments. The absence of pores 
from the seventh segment and their presence on the eleventh and 
fourteenth is a most remarkable character, and in connection with the 
flattened dorsum, elevated carinse, and nineteen segments, may easily 
necessitate the recognition of a monotypic family Batodesmidse, if 
forms connecting with Trachelodesmus are not discovered. The typi- 
cal and only specimen is dry and had been broken and mended with 
glue. It is not impossible that a segment had been lost, which would 
modify the latter part of the pore-formula, but as the specimen is a 
male the want of pores on the seventh segment can be certified. 
Mav 30, 1896. 
