80 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. XXXV. 



Head large, with the front produced in the middle in a large, broad 

 median lobe, truncate at the extremity ; on either side of the median 

 lobe is a prominent triangular process ; on either side of the triangular 

 process the lateral margin is produced in a long acute spine-like 



process, which is about twice as long as the 

 triangular process; these projections prob- 

 ably represent the ocular processes, but the 

 eyes are entirely absent. The first pair of 

 antennae are short ; the two peduncular arti- 

 cles are subequal in length, but the second 

 is more slender than the first ; the flagellum 

 is composed of six articles. The second 

 pair of antennae are broken in all the speci- 

 mens. 



The first four segments of the thorax are 

 the largest, the first being somewhat shorter 

 than the three following; the fifth is the 

 shortest, being less than one-third as long 

 as the preceding segment; the sixth and 

 seventh segments are subequal in length 

 and are also short, but are about one and a 

 half times as long as the fifth; the lateral 

 margins of all the segments are rounded. 



The first segment of the abdomen is 

 short, not quite as long as the last thoracic 

 the terminal segment is large, with the lateral margins 

 somewhat rounded, and the extremity truncate. On the ventral 

 side of this segment at the extremity between the median line 

 and the uropod are five sharp teeth as in Munna fabricii Kr0yer. 

 The uropoda are minute, simple, consisting of a 

 single article, and are situated on either side of 

 the truncate extremity. The first pair of pleopoda 

 in the male are narrow, elongate, with lateral 

 margins straight and not expanded; the extrem- 

 ity is truncate. 



The first pair of legs are shorter than those fol- 

 lowing and are prehensile. The others are long 

 and ambulatory. 



About eight specimens of this species come FlG i3._munna trun- 

 from Station 2547, steamer Albatross, south of cat a. first plbo- 

 Marthas Vineyard, and were taken at a depth of P0DA OF MALE- 

 390 fathoms. Three other specimens were found at Station 2507, be- 

 tween Middle Ground and Halifax from a depth of 80 fathoms. 



The type from Marthas Vineyard is in the U. S. National Museum, 

 Cat. No. 38968. 



Fig. 12. — Munna truncata. 



segment 



