50 



BULLETIN 54, UNITED STATES NATIONAL MUSEUM. 



"The terminal segment of the abdomen equals in length any four 

 of the anterior abdominal segments; it is cylindrical in form, becoming 

 gradually wider toward the extremity; it terminates in a truncated 

 straight posterior margin, and in the middle line in a short oval 

 prolongation. 



"The antennules are stouter, as well as longer, than the antennae; 

 they are about as long as the cephalothoracic shield and the first seg- 

 ment of the thorax taken together. The basal joint is long and stout, 

 the second joint is very much shorter, the third and fourth shorter 



still; from the last joint of the 

 peduncle arise the two flagella, 

 of which the outer is longer as 

 well as stouter than the inner; 

 the outer flagellum is made up 

 of ten joints, of which the first 

 is very much the longest; it 

 diminishes gradually in width 

 toward the extremity; the inner 

 flagellum has four or five nar- 

 row elongated joints. 



"The antennae have a five- 

 jointed peduncle and a flagellum 

 about as long as the last two 

 joints. The first joint of the 

 peduncle is short, the second 

 long, with a short, cylindrical, 

 setose exopodite articulated at 

 its extremity; the third joint 

 is very short, the fourth and 

 fifth long and subequal. 



" I have not had a sufficient 

 amount of material at my dis- 

 posal to give an accurate ac- 

 count of the mouth appendages. 

 "The chelae are not remark- 

 able in any way except for the absence of an exopodite; they appear 

 to be perfectly similar in both sexes, and agree very closely with those 

 of the genus Sphyrapus (female), etc. The first joint is very much 

 stouter than any of the succeeding joints; the second is short and nar- 

 row and bears a spine on the inner side just before its articulation with 

 the next joint, which is extremely minute and might easily be over- 

 looked; it is wedged in between the second and third joints, and is 

 only apparent on the inner side of the limb. The fourth joint is 

 longer and stouter and has a number of hairs along the inner margin. 

 The two fingers cross at their extremity; they are serrate along the 

 margins which come in contact. 



FIG. 39. TYPHLAPSEUDES NEREUS (AFTER BEDDARD). 



