KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND. 22. N:0 7. 109 



Often bar ist die Verwandlung der Hyperien als eine erworbene, nicht als eine 

 ererbte zu betrachten, cl. h. das spate Auftreten der Hinterleibsanhange und die eigen- 

 thiimliche Fussbildung der Jungen sind nicht unit der gesehiehtlichen Entwieklung der 

 Amphipoden in Verbindung zu bringen, sondern auf Reehnung des Sehmarotzerlebens 

 der Jungen zu setzen.» 



These interesting statements of Fritz Muller will be discussed in the morpholog- 

 ical part of this treatise. Here follows the description of the male; the only specimen 

 in the collection of »Musee d'Histoire Naturelle de Paris» being a male, I have not seen 

 any female specimen. 



The body is longer and more slender than in Hyperoche Luetkeni, and the integu- 

 ment thinner and softer. 



The head is as long as the first two pergonal segments together, and somewhat 

 more broad than long. The antennal groove commences above the middle of the front 

 side of the head and reaches to the lower margin. The head is not twice as deep 

 as long. 



The eyes occupy the whole surface of the head. 



The first pair of antennae are fully as long as the second pair. The first joint of 

 the peduncle is very large, more long than broad, and almost twice as long as the two 

 following joints together; the second joint is shorter than the third. The first joint of 

 the flagellum is nearly as long as the head, and much longer than the whole peduncle, 

 thick, almost cylindrical, as broad at the apex as at the base, the inner side is richly provided 

 with long hairs. The second flagellar joint is short, equalling about a ninth of the length 

 of the first joint, but much thicker than the following joints, which are eighteen to twenty 

 in number; each joint is five to six times as long as broad. 



The second pair of antenna?. The first free joint of the peduncle is short and stout, 

 as long as the second, the last joint is almost as long as the two preceding ones together. 

 The flagellar joints are equal in length, about ten times as long as broad; they are 

 twelve in number. 



The perceon. The first and second segments are equal in length; the seventh seg- 

 ment is the largest of all. 



The epimerals of the first four pairs are somewhat shorter than the under margins 

 of the corresponding segments, those of the last three pairs are as long as the segments. 



The branchial sacks are fixed to the second to sixth pairs of pergeopoda. They are 

 considerably shorter than the corresponding femora. 



The first pair of perceopod.a, (PI. VII, fig. 28). The femur is elongate, fully three 

 times as long as broad, the front and hind margins are feebly curved. The genu is 

 smooth, as long as broad. The lower hinder corner of the tibia is produced, but the 

 spoon-shaped process does not reach farther than to the middle of the stem of the carpus, 

 it is tipped with minute hairs. The front margin of the carpus is feebly curved, the 

 hind margin is a little excavated. The carpal process is shorter than the rest of the carpus; 

 the hind margin is smooth, the front margin forms a knife-like, strongly serrated, edge, 

 like that described in Hyperoclie Luetkeni, the serration is composed of thirty-four to 



