18 



CARL BOVALLIUS, THE OXYCEPHALIDS. 



C. HYPERIIDEA CURVICORNIA. 



The first pair of antennae are fixed to the inferior 

 side of the head, they are curved (tf), the first joint 

 of the flagellum is very large, the following few in 

 number and subterminal (tf). The second pair are 

 folded (<3% or wanting (9). 



1. The femur of the sixth pair of perseopoda is not 



operculiform. 



CC 1. The second pair of perasopoda are transformed. 

 The seventh pair of perseopoda are not 

 transformed; the telson is free. 



CC 2. The second pair of perseopoda are not trans- 

 formed. 



ccc 1. The head is scarcely produced, not 

 forming a rostrum. The maxillse con- 

 sist of two lamina?. 

 CCCC 1. The seventh pair of perseo- 

 poda are reduced to two 

 or three joints. 

 The seventh pair of peraao- 

 poda are complete, not 

 transformed. 



cccc 2. 



ccccc 1. 



ccccc 2. 



The telson is 

 free, not co- 

 alesced with the 

 last ural seg- 

 ment. 



The telson is 

 coalesced with 

 the last ural 



segment. 



11. PHORCORAPHID.E. 



12. PRONOID^E. 



13. EuTHAMNEIDvE. 



14. LYCLEID.E 1 ). 



1) In my preliminary paper sSystematical list of the Amphipoda Hyperiidea, I thought it 

 convenient to place the genus Trypluena, A. BOECK, in the same family as Lyccea, DANA, and to apply to 

 the family, containing these two genera and the allies of Lyccea, the name Trypluenidce, which preceded 

 by nine years the family-name Lycceidce, proposed by CLAUS in 1879 in his systematical arrangement 

 of the Platyscelids. Further study of these interesting Hyperids has however convinced me that Try- 

 phcena is more closely allied to the genera Phorcoraphis, STEBBING, and Lycceopsis, CLADS, than to 

 Lyccea and the other genera placed there by CLAUS. It is principally the peculiar transformation of the 

 second pair of perseopoda that makes it desirable to place Tryphcena close to the other members of the 

 old family Phorcidtf, beacuse it would be very strange to suppose such a homologous development of 

 the same organ in genera not closely allied. To this characteristic come others which also, but not so 

 thoroughly, point to a closer relation between the three genera, Phorcoraphis, Lycteopsis, and Tryphcena, 

 as for instance the form of the sixth pair of peiseopoda, the form of the urus and its appendages, and 

 in some way the shape of the first pair of antennae. From the point of view of priority the family- 



