670 PROCEEDINGS OF THE NATIONAL MUSEUM. 



Last segment entire; movements agile. 



This suborder may retain its earlier name if the Chordeumatida; and 

 Craspedosomatidii! are recognized as disDin(;t families; otherwise the 

 second name must be used, as that is the older for the family and the 

 subordinal designation must be kept uniform with it. 



Suborder STRIARIOIDEA Cook. 



Striarioidea Cook, I'.raudtia, 1896, p. 8. 



Body subcylindric, composed of ^{(^ segments in the adult; capable of 

 being coiled in a very close spiral: exoskeletoii comparatively thick 

 and firm. 



Head small, included and concealed by the expanded first segment. 



Antenna' inserted near together, below the middle of the head, 



Labrum of male produced laterally into a large curved spine. 



First segment very large, hood-like, concealing the head. 



Segments with numerous abrupt and prominent carina*; setiferous 

 tubercles wanting; repugnatorial pores wanting. 



Last segment trilobed. 



Movements very slow. 



Family STRIAKlIDyl^: (Bollman). 



Striarmm Hollman, Bull. U. S. Nat. Mus., 1893, No. 46, p. 158. 

 StriariUlw Cook, Anu. N. Y. Acad. Sci., 1895, IX, p. 4. 



Body subcylindric, capable of being coiled into a very close spiral. 



Head small, mostly (;overed by the first segment; the face on each 

 side broadly and deeply depressed. 



Labrum in males prodnced at each end into a long decurved stylus. 



Eyes poorly developed, of few ocelli, remote from the antenna*. 



Antenn* insierted near together, below the middle of the head. 



Mandibles with 10 pectinate lamellii*, a dentate lamella, a molar tooth, 

 and a large masticatory plate; cardo very large; exposed surface of 

 stipes small (compared with other families), nearly flat, not areate. 



Mentum semielliptic. 



Median lobe with a styliform process on each side. 



First segment much larger than the others, expanded and produced 

 anteriorly, hood-like, concealing the head. 



Segments dorsally multicarinate longitudinally, and rough tubercu- 

 late; b<*low unicariimte. Carina* of equal size, the lateral carina* not 

 larger than the others. Median furrow present, including a tine ridge: 

 setigerous tubercles wanting. 



Supplementary margin regularly pectinate. 



Pedigerous lamina* anteriorly prominent. 



First, second, fourth, and antepenultimate .segments each witli one 

 pair of legs, the third and last two footless; the last two complete 

 rings; whole number of legs 50. 



