ISOPODS OF NORTH AMERICA. 



489 



rostrum which is truncate in front. On either side of the rostrum 

 there is an emargination for the recei)tion of the basal articles of the 

 first pair of antennte. Eyes wantnio-. Two small spines are situated 

 on the posterior margin, one on either side of the median line. The 

 tirst pair of antenna^ have the l)asal articles large and dilated. The 

 second article is very small. The third article is about half as long as 

 the second. The flagellum is composed of about twenty-nine articles 



Fig. 540.— Munnopsis typic.\ (Aftek G. O. Sahs). a, Maxilliped.s. /), Head (ventral view). 

 c, Fr. sr leg of male, d, Second leg of male, e, Ventral view of male. /, First antenna 



OK .MALE. f/. SE00NI> LEG OF FEMALE. A, EXTREMITY OF THIRD LEG. t, FiR.ST AND SECOND PLEO- 



poDs OF MALE, j", Third leg of male, k. Fifth LE<i of male. /, Third im.eopod of female. 



and extends to the middle of the second thoracic segment. The second 

 pair of antennte have the tirst three articles short and about sub- 

 etpial; the fourth article is equal in length to the tirst three taken 

 together; the fifth is eight times longer than the fourth article; the 

 sixth is about as long as the tifth. The tiagellum is composed of 

 numerous articles. The second pair of antenna? are many times 

 longer than the body. 



