398 DISCOVERY REPORTS 



Abdomen solidly built, the somites without spines, and with small rounded pleura. 

 Telson elongated, tapering to a point bearing a pair of minute spines. Eyes small, with 

 black pigment and an inner papilla (Fig. 136). 



Peduncle of antennule very stout, three-segmented, without otocyst ; outer flagellum 

 about I J times length of peduncle. Antenna (Fig. 13 c) with very large oval scale, with 

 small apical spine and a fringe of short setae on inner margin. 



Mandible not seen. Maxillule vestigial, apparently represented by a pair of small 

 papillae, without setae, on either side of upper lip. Maxilla (Fig. 13 J) with very large 

 setigerous exopod ; endopod small, unsegmented ; three vestigial inner laciniae without 

 setae. Maxillipede i (Fig. 13 e) with epipod and large exopod, the basal part of which is 

 wide and fringed with setae on the outer margin; endopod two-segmented, slender; 

 coxa and basis without setae. 



Maxillipedes 2 and 3 and legs 1-4 with small exopods without setae; endopods 

 slender, without setae. Leg 2 very long, but these and other appendages seem to be 

 quite soft and functionless. Leg 5 absent. 



Pleopod I is a delicate flattened structure, fringed with setae on either side and 

 enormously long, reaching nearly to the mouth region. In each of the specimens it is 

 more or less twisted and torn at the end, so that the real structure is difficult to make out. 

 Pleopods 2-5 of normal form, with appendix interna. Uropods large, the outer branch 

 serrated along the outer margin, and with apical spine. 



Gills rather large on maxillipede 3 and legs i and 2, smaller on legs 3 and 4. 



Zimmer, who does not say how many specimens he had ("ein Anzahl"), found one 

 in which leg 5 was present as an unbranched appendage of six segments, and in which 

 pleopod I did not differ from the rest except in being uniramous. He regarded this 

 specimen as female and the rest as male. 



THE SYSTEMATIC POSITION OF AMPHION AND AMPHIONIDES 

 The history of the genus Amphion has been summarized above and the suggestion 

 has been made that Amphionides is its adult state. Zimmer treated Amphionides as a 

 larva, but observed that it "erinnert ausserordentlich an die Gattung Amphion". It 

 seems to me that he might have gone further, and have claimed it as an adolescent 

 post-larval stage in the development of Amphion. 



Amphionides is certainly a post-larval form, as shown by the structure of the eyes and 

 all the appendages, and there is no real difficulty in assuming that it might develop 

 directly from Amphion, great though the necessary changes are. The older specimens 

 of Amphion commonly have the thoracic region swollen, and this swelling, which one 

 would otherwise attribute to the preservative, may really be a step towards the inflated 

 condition of Amphionides. Other details which suggest identity are the following : 

 (i) Form of exopod and presence of three laciniae only in maxilla. 



(2) Agreement in form of post-rostral spine. 



(3) Form of telson. The two small points at the apex in Amphionides correspond to 

 the minute bifurcation in Amphion. 



