﻿164 PROCEEDINGS OF THE NATIONAL MUSEUM vol. loo 



Right first antenna modified into grasping organ, with 22 joints; 

 first six joints symmetrical on both sides and similar to those in 

 female ; starting from the seventh to the twelfth the distal end of each 

 joint elongated distally in the form of a triangle. Number and 

 distribution of setae on first 12 joints same as for the female except 

 that joints 10 and 11 each have a spine in addition to setae (fig. 20, n) ; 

 one spine on each of joints 13 and 15 ; spine on joint 13 very strong, 

 almost twice as long as the segment itself; spine on joint 15 least, 

 only one-half the size of spine on joint 10, which is shorter than that 

 on joint 11. Middle section (joints 13-18) increasing in thickness 

 until the fifteenth, which is greatest in diameter. Antepenultimate 

 joint (fig. 20, k) provided with a nearly straight process on distal end, 

 with its tip bent and a thin hyaline lamella on the outer edge of the 

 process; last two joints not armed with appendages except for those 

 found on the left, or on the female, antenna. Maxilliped and first four 

 pairs of legs similar to those of female (e. g., fig. 20, 1) . 



Fifth pair of rudimentary legs asymmetrical, greatly modified. On 

 right side first basal segment smaller than second, with a stout spine on 

 outer distal end pointing caudally ; second basal segment cylindrical, 

 with hyaline spine on proximal end of mesial surface and only one 

 rounded, though much larger, hyaline protuberance instead of two 

 such structures, shorter in length, found in T. hehereri/ sensory hair 

 present on distal end of outer surface. Endopodite simple, nearly as 

 long as first exopodite segment, possessing one distinct, though short, 

 spine on distal end of mesial surface and a number of small hairs on 

 terminal end. This spine has not been described for T. hebereri at this 

 position. First exopodite segment rather small, with two large hyaline 

 spines on distal end, one mesial, one lateral ; second exopodite segment 

 with a long curved outer or posterior border, with a stout claw, equaling 

 the whole second exopodite segment in length and dentate along its 

 concave surface ; arising slightly above the middle point of this border, 

 on the middle of the lower half, between the two claws, a rounded hya- 

 line protuberance occurs, and above it a strong but short spine arises. 

 Terminal claw long, sickle-shaped, dentate on concave side, sometimes 

 as long as the whole leg. Left leg small each joint being correspond- 

 ingly smaller than right ; first basal segment also smaller than second, 

 carrying on outer caudal surface a spine as big as that on the right leg ; 

 second basal segment cylindrical, nearly twice as long as broad, with 

 a sensory hair on outer distal corner. Endopodite simple, un jointed, 

 with a number of short bristles on distal end. Exopodite modified into 

 a structure comparable to that described by Kiefer for T. hebereri (fig. 

 20, m, and cf . Kiefer, 1934) . 



A large number of males and females were collected from Lake 

 Erh Hai in Yunnan at different times of the year. In November they 

 represent the most abundant copepod among the plankton. 



