158 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 40. 



behind the constriction instead of in front as in 0. ohustus. The 

 hindbelt is also somewhat shorter than in 0. ohustus, so that the 

 repugnatorial pores are brought closer to the posterior margin of the 

 segment. The lateral suture is indicated by a fine groove behind 

 the pore, but not so pronounced as in 0. ohustus. 



Last segment somewhat less produced than in 0. ohustus but the 

 apex distinctly angular, instead of being completely rounded off as 

 in 0. ohustus. Penultimate segment very short, the margin scarcely 

 exposed. 



Anal valves somewhat more convex and prominent than in 0. ohus- 

 tus, and with a less distinct row of fine hairs along the margin. Pre- 

 anal scale thinner and somewhat angular like the apex of the segment. 



Five specimens, three evidently immature and the others possibly 

 so. The only complete specimen is a male with 38 segments, but 

 only about 12 mm. long. 



ONYCHELUS DENTATUS, new species. 



Type. — Cat. No. 804, U. S. National Museum, collected at Fort 

 Huachuca, Arizona, by T. E. Wilcox. Accession No. 26403. 



Diagnosis. — Similar in size and shape to Onijchelus ohustus, but 

 having the lateral angles of the first segment acute and striate, the 

 transverse constriction very shallow and indistinct, the pores closer 

 to the posterior margin, and the lateral suture not marked by a 

 distinct groove. 



Description. — Body about 40 mm. long with a diameter of 4.5 mm., 

 composed of 48 segments. 



Color of alcoholic specimen very deep olive green, nearly black; 

 legs and antennse also dark, with a bluish tinge. 



Clypeal foveolse five on each side, the outer pair close to the margin 

 and smaller than the others. Surface of clypeus with a few irregular 

 impressed lines ; otherwise evenly convex but scarcely shining. 



Eyes composed of nearly 40 ocelli, arranged in seven rows, counted 

 as follows: 4, 6, 6, 7, 7, 4, 2, and 5, 6, 7, 7, 6, 5, 3. 



First segment with the lateral corner acute, more produced than 

 in O. ohustus or 0. hospes, the anterior raised margin more pronounced 

 and the posterior margin striate or grooved near the angle like the 

 sides of the other segments. The raised margin is carried farther 

 back around the corner than in 0. ohustus and even projects very 

 slightly, so that the posterior margin appears slightly emarginate just 

 above the corner. 



Segments very minutely and indistinctly punctate-coriaceous on 

 the surface, the punctations more distinct than in 0. ohustus, but 

 less distinct and less numerous than in 0. hospes. The transverse 

 constriction is very slight, but follows the posterior suture, so that 

 the pores are in the line of the constriction. The lateral suture is 



