and species of the Family Pselaphidse 33 



b. Tarsi' with one claw. 



PSELAPHUS. Herbst. 



Maxillary palpi with the last joint club-shaped, very long. 



P. Eriohsonii, Lee, differs from the southern form P. longiclavus by the last joint 



<if the maxillary palpi, which is pedunculate from the middle 

 of it- length. Long 1.75 m, m. Sab. — Northern States. 

 P, longiclavus. Lee. Long 1.8 m. m. Last joint of the palpi a long club. 

 Sab.— Southern States. 



TYCHTJS, Leach. 

 Maxillary palpi with the third joint triangular and the last joint 



hatchet-shaped. 



T. longipalpus, Lee. The third joint of the palpi is as long as the last and 

 nearly cylindrical, the anterior coxa? are armed with a spine in 

 %. Long 1.7 m. m. Hab. — Northern States. 



T. minor, Lee. The thorax is shorter and rounded than in T. longipalpus, two 

 punctures before the eyes, the third joint of the maxillary palpi 

 is triangular. Lung 1.4 m. m. Hab. — Northern States. 



T. puberulus. Lee. Third joint of the palpi long, cylindrical ; anterior and pos- 

 terior coxae of the % armed with curved spines. Long 1.6 m. 

 m. Sab. — California. 



T. tenellus, Lee. Third joint of the palpi small, triangular. Stature slender, 

 shining. Long 1.3 m. m. Hub. — California. 



T. bythinioides, Brendel. Third joint of the palpi globular, small ; first joint of 

 the antennas very long, cylindrical; the second large, globular; 

 the following small, transverse; the last large, hatchet-shaped. 

 Long 1.4 in. m. Hab. — Eastern States. 



The Bryaxes are divided in those with the abdomen strongly mar- 

 gined, which have all only a single claw on the tarsi, and those with 

 the abdomen not margined, which are represented by the genus Batri- 

 sus and the sub-genus Arthmius, and have two unequal tarsal claws. 



I. — Abdomen margined, tarsi with one claw. 

 BYTHINUS. Aube. 

 Maxillary palpi with the last joint securiform. Antenna) 11-jointed. 



B. carinatus. Brendel. The maxillary palpi, second joint long, clavate; third 

 small, globular; fourth large, hatchet-shaped. The antennae, 

 first joint long, cylindrical; second large, globular; the bead 

 carinate above, each side before the eyes a small groove. Long 

 1.66 in. in. Sab. — Pennsylvania. 



B. zonatus, Brend. 1. The head is plane with two small grooves, the last an- 

 tennal joinl very large, the other joints, except the two first, 

 small, transverse; the thorax has one groove and a punctured 

 zona at the base. Lung 1.2 m. m. Sab. — Atlantic Seacoast. 



BRYAX1S. Leach. 

 Last joint df the palpi fusiform. Antennae 11-jointed. 

 j Thorax with a basal transverse sulcus and threi equal grooves. 

 a. The thoracical sulcus connecting the three basal grooves. 



PROCEEDINGS EST. SOC. 1'IULAD. MAY, 1866. 



