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



147 



1. HYPERIA MEDUSAIttJM, 0. F. MULLER, 1776. 



PI. IX, fig. 1—21. 



Pulex cancriformis, antennis brevisshnis, 

 H. Strqm. 



Facsimile from Str0m, S0ndm0r, pi. 1, fig. 12 and 13. 



Talitrus cyanea, Sabine. 



Facsimile from Sabine, Crust, of Supp. to Append, of Parry's 

 voyage, pi. 1, fig. 12 — 18. 



Pig. 1. The male. 2. The female. 3. The head of the 

 same. 4. The first pair of antennae of an adult male. 

 5. The same pair of a youuger male. 6. The second 

 pair of peraeopoda. 7. The urus. 



Diagn. Caput curtum, latum, segmenta duo priora perasi longitudine aequans. Segmenta omnia perm 

 libera. Carpus pedum percei primi paris dilatatus, non productus, spinis longissimis in- 

 dutus, margo posterior leviter incisus. Carpus pedum secundi paris paullo pi-oductus, 

 spinis longissimis indutus. Metacarpus pedum primi et secundi parium ovatus, spinis 

 longissimis indutus, margo posterior incisus, non serratus; dactylus parvus, spinis obtectus. 

 Pedes tertii ac quarti parium pedibus parium duorum prascedentium paullulo longiores, 

 spinis longis liberaliter instructi. Pedes parium trium ultimorum duobus prascedentibus 

 non longiores; femur angustum, carpus metacarpusque leves, non serrati. Latera segmen- 

 torum plei duorum ultimorum angulata. Pedunculus pedum uri ultimi paris latissimus. 

 Telson non longius quam latius, segmentum ultimum uri longitudine asquans, pedunculo 

 pedum uri ultimi paris non angustius, ac dimidio pedunculi ejusdem longius. 



The head is short and broad, as long as the first two peraeonal segments together. All the 

 perceonal segments are free. The carpus of the first pair of pertvopoda is dilated, not 

 produced, covered with very long bristles; the hind margin is feebly notched. The 

 carpus of the second pair is a little produced, covered with very long bristles. The meta- 

 carpus of the first and second pairs is egg-shaped, covered with veiw long bristles, the 

 hind margin is notched, not serrated; the dactylus is small, hidden by bristles. The third 

 and fourth pairs are only a little longer than the two preceding pairs, thickly set with 

 long bristles. The last three pairs are not longer than the two preceding pairs; the 

 femur is narrow, the carpus and metacarpus are smooth, not serrated. The lateral parts 

 of the last two pleonal segments are angulated. The peduncle of the last pair of uropo da 

 is very broad. The telson is not longer than broad, equalling in length the last ural 

 segment; it is not narrower than the peduncle of the last pair of uropoda, and more than 

 half as long as the same peduncle. 



