38 PROCEEDINGS OF THE NATIONAL MUSEUM vol.82 



The first segment of the exopod is short with a spine at the outer dis- 

 tal angle; the second segment of the exopod is a flat plate, squarely 

 truncate at the distal end; it has a spine at each distal angle and the 

 distal margin is finely denticulated. 



Length, 1.3 mm. 



OcGV/rrence. — Found in Burma. 



PSEUDODIAPTOMUS PELAGICUS Herrick 



Plate 19, Figukes 5, 6; Plate 20, Figure 2 



Pseudodiaptomus pelagicus Heerick, 1884, p. 181 ; 1887, pp. 10, 11. pi. 1, fig. 8, 

 pi. 2, figs. 1-8.— Herbick and Ttjenee, 1895, p. 53, pi. 1. figs. 11-17.— 

 Giesbeecht and Schmeil, 1898, p. 64. 



Female (pi. 19, fig. o). — Head rounded, beaked, and separated from 

 the thorax. The sides of the last thoracic segment are pointed. The 

 abdomen has three segments. The furcal rami are elongated and 

 have spines on the margins. The first antennae have 22 segments 

 and extend to the furca. In the fifth feet (pi. 19, fig. 6) the first 

 segment of the exopod is elongate, and has a spine at the inner distal 

 angle and a group of small spines on the distal third of the inner 

 margin. At distal end of the second segment of the exopod there 

 is an external spine and a stout internal spine. The terminal hook 

 is falciform, dentate on the inner border, and much longer than 

 the second segment of the exopod. Ovisac single. 



Mole. — In the male fifth foot (pi. 20, fig. 2) the second segments 

 of the basipods are armed, on the inner borders, with a mass of 

 rather coarse spines. The first segment of the exopod of the right 

 foot has a row of spines on its inner border and two rather long 

 spines, one near the proximal end and the other at the inner distal 

 angle. The lateral spine of the second segment of the right exopod 

 is situated at about three-fourths the length of the segment. The ter- 

 minal hook is about as long as the two segments of the exopod. The 

 second segment of the basipod of the left foot has, besides the spines 

 of the inner border, four spines on the outer border. There is a 

 spinelike endopod that exceeds the length of the first segment of the 

 exopod. The first segment of the exopod has a slender spine at its 

 outer distal angle. The second segment is twice as long as the 

 first and terminated by four spines. 



Occurrence. — Found in Mississippi Sound. 



Remarks. — The description is from the statements and figures of 

 Herrick. No other collections of the species have been reported. 

 The figures are taken from Herrick; while they are diagnostically 

 sufficient, there is some question of their accuracy, especially of those 

 of the fifth feet. 



