Genera and Species of Scolopendridae. 61 



Allied to the widespread Rh. longipes of Newport, but 

 differing in its much longer antennae and in the irregular 

 arrangement of the spines on its anal femora (there being no 

 apical spine). 



Rhysida calcarata, sp. n. (PI. IV. figs. 6, 6 a.) 



Body slender, almost parallel-sided. 



Colour olivaceo-ochraceous, legs testaceous ; shining with 

 submetallic lustre. 



Head-plate sparsely punctured. 



Antenna} long, composed of seventeen to twenty-one seg- 

 ments, whereof the basal three are bare, the rest pubescent, 

 the segments much shorter than in Rh. longicornis. 



Maxillary sterm'te entire, sparsely punctured ; prosternal 

 plates wider than long, almost in contact, each bearing four 

 teeth ; basal tooth well developed and subdentate. 



Tergites smooth, from the fourth bisulcate, from the eleventh 

 or twelfth with raised margins. 



Sternites smooth, bisulcate, the sulci extending considerably 

 past the middle of the plate, but becoming indistinct poste- 

 riorly. 



Anal somite. — Tergite not sulcate and not impressed 

 behind; pleurce densely porous, with well-developed some- 

 what slender process, which is armed with one lateral and 

 four apical or subapical spines ; sternite narrowed posteriorly, 

 with almost straight or lightly concave hinder border ; legs 

 somewhat short ; femur armed with about fifteen spines — -six 

 or seven in two rows on the upper inner edge, two to four on 

 the under inner edge, and from three to five on the under 

 outer edge ; the posterior process is well developed, in one 

 specimen (? ? ) it is short, very wide, and armed with eight 

 or ten spines, in two others (? $ ) it is long, slender, cylin- 

 drical, blunted, and armed with five or six spines ; tarsus not 

 spined ; claw with two basal spurs. 



Legs. — Twentieth pair either with or without a tarsal spur, 

 nineteenth to seventeenth with one tarsal spur each, sixteenth 

 to first with two tarsal spurs ; first pair with a spine upon the 

 femur, patella, and tibia ; claws of all the legs spined. 



Three specimens from Cambodia ; one of these, measuring 

 57 millim., is larger than the others, has the antennas com- 

 posed of seventeen segments, the anal legs more slender and 

 the femoral process short and wide ; in the others measuring 

 about 36 millim., the antenna? are composed of twenty-one 

 segments, the anal legs are stouter, and the femoral process 

 much longer. I suspect that the last two are the males and 



