NO. 1876. ON THE CRUSTACEAN ORDER CUMACEA—CALMAN. 



673 



The peduncle of the iiropods is about two and a half times as lono- 

 as the last somite, with a row of rather longish spines on its inner edge. 

 The exopod is about half as long as the peduncle and the endopod 

 about three-quarters as long as the exopod. The endopod is composed 

 of three segments, of which the first is nearly four times as long as 

 the other two together; the terminal segment is of very unusual form, 

 having a strong compressed spine produced backward from its lower 

 surface and projecting far beyond the bluntly rounded tip. Both 

 exopod and endopod bear spines on their outer and inner edges. 



Adult male. — Total length, 11.8 mm. 



Resembling the female except that the general form is more slender, 

 with the cephalothoracic region less inflated and the carapace slightly 



107 108 109 



Figs. 107-109.— Colurosttlis (?) occiden.talis, female. 107, Second leg; 108, thikd leg; 109, a, last 



SOMITE, TELSON, AND UBOPOD FROM ABOVE; 6, TIP OP ENDOPOD FROM THE SIDE, FURTHER ENLARGED. 



depressed. The ridges of the carapace are less prominent and the eye 

 much larger and more distinct, although without pigment. There is 

 no dorsal keel on the tliird free thoracic somite, but the fourth 

 somite is as in the female. The expanded pleural plates of the 

 third somite are somewhat swollen and are separated from the dorsal 

 part of the somite on each side by a shallow groove in line with the 

 pleural suture of the fourth somite. Each of the first two abdominal 

 somites has a strong, backwardly curved tooth in the midventral 

 line in front of the attachment of the pleopods, and each of the three 

 following somites has a pair of articulated spines on the ventral side 

 beliind the middle of its length. The telson is longer than in the 

 female, with the dorsal surface hollowed; its rounded distal edge 

 94428°— Proc.N.M.vol.41— 11 43 



