22 



Carl Bovallius, 



The second Family. 

 TRlSCHIZOSTOMATIDiE. G. SARS. 



Syn. 1860. Prostomatœ. 



1865. Trischizostomalina. 



1870. Prostomatœ. 



1872. 



A. BOECK. 



1882. Triscliizostoniidœ. G. O. SARS. 



A. BOECK. Forhandl. ved de Skandinaviske Natur- 



forskeres 8:de Mode. p. 637. 

 W. LILLJEBOEG. »Bidrag till kännedomen om under- 

 familjen Lysianissina inom underord- 

 uingen Ampliipoda bland kräftdjuren», 

 p, 9. in Upsala Universitets Årsskrift 

 1865. Matematik och Naturvetenskap. 

 „ »On the Lysianassa magellanica», etc. 



p. 17, in Nova Acta Reg. Soc. Se. 

 Upsaliensis. Ser. III, vol. VI. 

 »('rustaeea amphipoda borealia et arc- 

 tica». p. 10. in Christ. Vidensk. Selsk. 

 Forhandlinger for 1870. 

 De skandinaviske og arktiske Amphi- 

 poder. p. 95. 4:to. 

 »Oversigt af Norges Crustaceer», etc. I. 

 in Christ. Vidensk. Selsk. Forhandlin- 

 ger 1882, N:o 18. p. 20. 

 Diagn. The head triangular, not tiimid. 



The eyes large, occupying the sides of the head, distinctly faceted. 



The mandibles styliform, with a strong three-jointed j^alp. 



The maxillipeds coalesced along the middle, forming a gouge-like operculum 



for the mouth-organs, carrying a foui'-jointed palp. 

 The antennoi are fixed on the under-side of the head. The second pair of 



antennae like those of the Gammarids. 

 The seventh pair of jjereiopodxi not transformed. 

 The uropoda like those of the Hyperids. 

 The telson simple. 



Only one genus Trischizostoma, A. Boeck. The young ones of 

 Trischizostoma Raschii show an interesting feature pointing to their 

 relationship with the preceding family, in the exterior ramus of the last 

 pair of uropoda being bi-articulate and the telson cleft or rather in- 

 cised to less than a fifth of its length. These characteristics are totally 

 changed in the adult animal. In the large epimerals of the second to 

 fourth pereional segments the animals belonging to this family show 

 another resemblance to the Synopidse, a feature which reappeares in the 

 family Hyperiopsidee, but in a lower degree. 



