Amphipoda Synopidea. 23 



Gen. 1. Trischizostoma. A. BOECK, 1860. 



Syn. 1860. TrisMîostoma A. BOECK. Forhaiullinger ved de Skaiul. Na- 



turforskeres 8:de Mode. p. 637. 



1865. ,, W. LiLL.iisBORG. »Bidrag till kännedomen om un- 



derfamiljen Lysianassina inom 

 underordningen Amphipoda bland 

 kräftdjuren», p. 9, in Upsala Uni- 

 versitets Årsskrift, 1865. Mate- 

 matik och Naturvetenskap. 

 ,, „ „ ,, »On the Lysianassa magellanica», 



etc. p. 17, in Nova Acta Reg. 

 Soc. Se. Upsaliensis, Ser. III, 

 vol. VI. 



1870. ,, „ A. BoECK »Crustacea borealia et arctica». 



p. 10. in Christ. Videnskabs 

 Selsk. Forhandlinger for 1870. 



1872. „ „ De Skandinaviske cg Arktiske 



Amphipoder. p. 96. 4:to. 

 Diagn. Corpus latum, non compressum. 



Caput latum, triangulatum, ante in rostrum latum, crassum, in apice rotunda- 

 tum, productvmi. 



OcuU grandes, in medio capitis non confluentes, ocellis magnis. 



Antennœ primi paris flagello multi-articulato instruct«, articulum primum fla- 

 gelli crassum, elongatum. 



Pedes j)ereii primi paris metacarpo permagno, inflate, semicirculari ; dactylo in 

 angulo inferiore posteriore afifixo. Pedes pereii quarti paris tibia elongata, 

 valde dilatata. Pedes trium parium ultimorum dactylis modicis, robustis. 



Pedes uri ultimi paris ramis lanceolatis, integris. 



Telson magniun. 



The body is broad, not very compressed. 



The head is broad, triangular anteriorly produced into a broad, 

 thick rostrum, rounded at the tip. 



The eyes are large, not coalesced in the middle of the head, with 

 distinct large ocelli. 



The first pair of antennœ with a multi-articulate flagellura, the 

 first joint of the flagellum thick and long. 



The first pair of pereiopoda have a very large, tumid, semicircular 

 metacarpus, the dactylus is articulated against the hinder lower corner 

 of the metacarpus. The fourth pair with the tibia very broad and long. 

 The last three pairs with robust, but not very long dactyli. 



The last pair of uropoda with the exterior rami lanceolate, not 

 bi-articulate. 



The telson is large. 



Only one species is hitherto known. ".■•' 



