538 



BULLETIN 54, UNITED STATES NATIONAL MUSEUM. 



"Thorax: The pleural plates are very large oval lamella 1 , only con- 

 nected with the segment by somewhat less than the posterior half of 

 their interior margin, and this result is due to the fact that they 

 anteriorly are very much produced, highly overlapping each other, 

 and posteriorly rather shortly produced. The legs are tolerably 

 slender; the second joint not expanded; the fifth joint elongate, in 

 the last pair as long as the hand. 



"Abdomen: It is turned to the left in a startling degree and is pro- 

 portionally small perhaps very small. The dorsal surface is soft- 

 skinned, the segments more or less dis 

 tinctly separated. Pleural plates are not 

 developed. The pleopods quite soft, of 

 medium size, decreasing conspicuously 

 in size from before backward and at- 

 tached to the lateral margin; each pleo- 

 pod consists of a short peduncle and 

 two lamellar oblong rami; the outer 

 ramus much larger than the inner one. 

 The uropods biramous; the outer ramus 

 a little smaller than the outer of the 

 fifth pleopod, the inner ramus very 

 short, almost rudimentary. The pleo- 

 pods are curled to such a degree that it 

 would have been impossible without 

 much construction to draw a sketch of 

 the abdomen. 



"(&) Male. The body is a little more 

 than three times longer than broad, and 

 from the fourth thoracic segment it 

 decreases in breadth towards both ends. 

 (Fig. 5811.) 



' ' Head : The dorsal surface rather con- 

 vex; the median portion of the anterior 

 margin almost straight. No eyes. The 

 frontal border bent slightly downward. 

 (Fig. 581$. ) The antennulte rather 

 short, three-jointed; the basal joint tol- 

 erably thick and partly overlapped by the rostrum; the second joint 

 slender and rather short; the third very small. The antenme com- 

 paratively long, seven-jointed; the four proximal joints of about 

 the same length, but decreasing much in breadth from the rather 

 thick basal joint to the fourth one; the fifth joint is short and very 

 slender, the last two joints exceedingly small. The mouth forms a 

 rostrum, which, when seen from below, is triangular, considerably 

 depressed, and directed forward, reaching almost to the frontal margin 



FIG. 581. BATHYGYGE GRANDIS (AFTER 

 HANSEN). a, HEAD OP MALE (YEN 

 TEAL VIEW). 6, DORSAL VIEW OF MALE. 

 C, FIRST LEG OF MALE, d, FIFTH LEG OF 



MALE. 



