22 



Carl Bovallius, 



The second Family. 

 TlU8CIIIZ0ST0I^IATIDiE. G SARS. 



Svn. 



1860. Prostomatce. 



1865. TrischizostoniatiiKi. 



1870. Prostoinalii:. 



A. BOECK. 



1872. 



1882. 



Triscliizostuiiiiihv. G. 0. oAKb. 



A. BOECK. Foi-handl. ved de Skaiuliiuiviske Natur- 



forskei'es 8:de Mode. p. 637. 



W. LILLJEBOKG. »Bidrag till kannedomcii oui uiidcr- 

 farailjen Lysianissina iiiom undcrord- 

 iiingen Araphipoda bland kraftdjureuw. 

 p. 9. in Upsala Universitets Arsskrift 

 1865. Matematik och Naturvetenskap. 

 „ »0n the Lysianassa niagellanicaH, etc. 



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

 Upsaliensis. Ser. Ill, vol. VI, 

 »('rustacoa amphipoda borealia ct arc- 

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

 Forhandlinger for 1870. 

 De skandinaviske og arktiske Amphi- 

 poder. p. 95. 4:to. 

 ))Oversigt af Norses Cri;staceer», etc. I. 

 in Christ. Vidensk. Selsk. Forhandlin- 

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



Diagn. The head triauguhir, not tumid. 



The cijes large, occupying the sides of tlic liead, distinctly faceted. 



The mandibles styliform, with a strong three-jointed palp. 



The maxiUqwdfi coalesced along the middle, forming a gouge-like ()])er('ulum 



for the mouth-organs, carrying a four-jointed palj). 

 The antennce are fixed on the under-side of the head. The second j)air of 



antenna) like those of the Gammarids. 

 The seventh pair of pereiopoda 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 rosend)lance to the Synopidaj, a feature which reappeares in the 

 family Hyperiopsidse, but in a lower degree. 



