KONGL. SV. VET. ARADEMIENS HANDLINGAK. BAND. 22. N:0 7. 233 



20. HYPERIA THORACICA, n. sp. 



PL XI, fig. 37—41. 



Diagn. Caput magnum, dimidio partis coalitje peraai haud longius. Segmenta quinque prima percei 

 coalita, cetera libera, post acute producta. Carpus pedum pera>i primi paris dilatatus et 

 paullo productus. Carpus pedum secundi paris productus; margo anterior processus car- 

 palis dimidio marginis posterioris metacarpi paullo longior. Metacarpus pedum primi et 

 secundi parium spinam singulam margini anteriori affixam gerens; margo posterior serratus, 

 dentibus simplicibus; dactylus longus. Pedes tertii ac quarti parium pedibus parium duorum 

 prsecedentium paullo longiores; carpus spinam singulam gerens; metacarpus serratus; dac- 

 tylus longus. Pedes parium trium ultimorum duobus prascedentibus haud longiores; femur 

 paullo dilatatum; carpus tibia non brevior; metacarpus non serratus; dactylus longus. 

 Segmenta plei post acute producta; latera segmentorum post angulata. Pedunculus pedum 

 uri ultimi paris quater longius quam latins. Telson lingulatum, longius quam latius, 

 segmento ultimo uri brevius, pedunculo pedum uri ultimi paris latius, ac dimidio pedunculi 

 ejusdem paullo brevius. 



The head is large, about half as long as the coalesced part of the perason, The first five 

 perceonal segments are coalesced, the last two are free, and dorsallv produced backwards, each 

 into a sharp point. The carpus of the first pair of perwopoda is dilated, and a little pro- 

 duced. The carpus of the second pair is produced; the front side of the carpal process 

 is somewhat more than half as long as the hind margin of the metacarpus. The meta- 

 carpus of the first and second pairs is provided with a single bristle on the front margin; 

 the hind margin is serrated, with simple teeth ; the dactylus is long. The third and fourth 

 pairs are a little longer than the first and second; the carpus carries a single bristle; the 

 metacarpus is serrated; the dactylus is long. The last three pairs are scarcely longer than 

 the two preceding; the femur is a little dilated; the carpus is not. shorter than the tibia; 

 the metacarpus is not serrated; the dactylus is long. The segments of the pleon are dor- 

 sally produced backwards, each into a sharp point; the lateral parts of the segments are 

 angulated behind. The peduncle of the last pair of uropoda is four times as long as broad. 

 The telson is tongue-shaped, longer than broad, and shorter than the last ural segment; 

 it is broader than, and not half as long as, the peduncle of the last pair of uropoda. 



Colour Light red. 



Length. 4—5 mm. 



Hab. The tropical region of the Atlantic: Between Lat. 20°— 13° N. and Long. 43°— 50° W. 

 (D. M.; F. M.; S. M.) 



Hyperia thoracica is distinguished from its congeners, by the sharp-pointed, dorsal 

 prolongations of the last two pergonal segments, and of all the pleonal, as well as by the 

 coalition of the first five peraeonal segments. 



K. Sv. Vet. Ak. Handl. Band. 22. N:o 7. ^V 



