KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND. 22. N:0 7. 145 



4. The armature of the metacarpus of the first and second pairs of peraeopoda, if smooth 



on the hind margin — or serrated; if more or less thickly set with bristles — or 

 naked. 



5. The carpus of the third and fourth pairs, if smooth, — set with bristles — or serrated. 



6. The carpus and metacarpus of the fifth to seventh pairs, if smooth, — or serrated. 



7. The peduncle of the last pair of uropoda, if broad, — or narrow. 



8. The relation of the telson to the last ural segment, and to the breadth and the length 



of the peduncle of the last pair of uropoda. 



The following synoptical table will show the systematical order of the species accord- 

 ing to my views as to their mutual relations. 



A. All the peraeonal segments are distinct, free. 



a 1. The metacarpus of the first and second pairs of peraeopoda is densely 

 covered all over with longer or shorter bristles. The carpus also of the 

 third and fourth pairs is thickly set with bristles. 



aa 1. The dactylus of the first pair of perasopoda is shorter than the sur- 

 rounding bristles. The bristles are very long _ _. 1. II. nieriusariiiii. 



aa 2. The dactylus of the first pair of perasopoda is much longer than the 



surrounding bristles. The bristles are very short, spine-like 2. II. lijstriv. 



a 2. The metacarpus of the first and second pairs of perasopoda is sparingly 

 provided with bristles on the sides. The carpus of the third and fourth 

 pairs without bristles or with few. 



aa 3. The first pergonal segment is shorter than or equal to the second 

 in length. 



aaa 1. The front side of the carpal process of the first pair of 

 peraeopoda is not more than half as long as the hind margin 

 of the metacarpus. 

 aaaa 1. The uropoda are broad and stout. 



aaaaa 1. The telson is more than half as long as the ped- 

 uncle of the last pair of uropoda 3. II. Latreillei. 



aaaaa 2. The telson is not half as long as the peduncle of 

 the last pair of uropoda. 

 aaaaaa 1. The hind margin of the metacarpus of the first 

 two pairs of peraeopoda is serrated, but not 

 notched, nor fringed with spines. 

 aaaaaaa 1. The front side of the carpal process of 

 the first pair of perasopoda is much 

 shorter than half the hind margin of the 

 metacarpus. 

 aaaaaaaa 1. The serration on the hind margin 

 of the metacarpus of the first pair 

 of peraeopoda consists of simple 



teeth 4. II. Gauilirliauilii. 



19 



K. Sv. Vet. Akad. Handl. Band. 22. N:o 7. ±D 



