1896.] NATURAL SCIENCES OF PHILADELPHIA. 257 



SUMMARY OF NEW LIBERIAN POLYDESMOIDEA. 



BY O. F. COOK. 



In a preceding paper' on the diplopod fauna of Liberia several new 

 species and genera were referred to, of which a list is here given to- 

 gether with such additional diagnostic characters as may be neces- 

 sary for the separation of the various forms from the territory 

 explored. Extended descriptions and plates are in preparation. 



Ammodesmus granum. 



Locality, Mt. Coffee, a cluster of hills in western Liberia, reach- 

 ing an altitude of about 300 feet, and covered with dense forest. A 

 large part of the other forms were collected in the same vicinity, all 

 except those of which other localities are specified. 



Cenchrodesmus volutus. 



Length about 2 mm., width .65 mm. 

 Campodesmus carbonarias. 



Surface of head and segments covered with rough granules ; first 

 segment scarcely broader than the head, with three transverse rows 

 of coarse tubercles ; second segment broadest of all ; segments with 

 a cluster of three large tubercles on each side of the middle, five 

 smaller scattered tubercles on each side of these, and three tubercles 

 on each of the very broad, decurved carinse ; last segment not con- 

 cealed, rounded at apex, with three broad, blunt, setigerous tuber- 

 cles on each lateral edge ; preanal scale with two long smooth seti- 

 gerous papillae. Length of male 29 mm., width 5.25 mm. ; length 

 of female 32 mm., width 6.5 mm. 



Tropidesmus jugosus. 



Generally similar to the preceding, except that the segments are 

 dorsally ornamented with two transverse rows, each of six short lon- 

 gitudinal carinie ; also the tubercles of the preanal scale are short, 

 not papilliform. Length 28 mm., width 5 mm. ; locality Mt. Coifee 

 and vicinity ; much rarer than Campodesmus, and more inclined to 

 burrow in the ground. 



*A New Diplopod Fauna in Liberia. American Naturalist, xxx, pp. 413- 



420, 1896. 



