Superfamily HOPLOPHOROIDA. 



Family Hoplophoridae. 



The family Hoplophoridae contains the seven genera Hoplophortis H. M.-Edw., Systellaspis 

 Bate, Acajithephyra A. M.-Edw., Ephyrina S. I. Smith, Notostovius A. M.-Edw., Hymenodora 

 G. O. Sars and Gonatonotns A. M.-Edw. As regards the genus Menitigodora S. I. Smith, 

 established in 1882 for a species, taken at 1632 fathoms off the east coast of the United States 

 and which in 1888 was united by Spence Bate with the genus Hymenodora G. O. Sars, I would 

 remark that in my opinion it must be identified, not with the genus Hymenodora^ but with the 

 genus Acanthephyra A. M.-Edw. The oral appendages, indeed, are just like in Acatithephyra, 

 a fact already observed by S. I. Smith himself, for in his detailed description of Meningodora 

 mollis (in: Bull. Mus. Comparat. Zoology, Vol. X, N" i, Cambridge 1-882, p. 74) this author 

 says: the oral appendages are all very nearly as in Miersia Agassizii (i.e. in Acanthephyra 

 purpurea), the differences being no greater in fact than might be expected between species 

 belonging to the same genus. The endopod of the first maxilliped is composed of three segments 

 and the two inner distal lobes of the second maxilla are narrow and project considerably beyond 

 the basal lobe (S. I. Smith, 1. c, Plate XII, Figs. 7 and 8), in Hymenodora G. O. Sars, on 

 the contrary, the endopod of the first maxilliped is biarticulate and the two inner distal lobes of 

 the second maxilla are broad and do not project beyond the basal lobe. It was the general 

 appearance of Meningodora mollis^ so conspicuously different from that of the species of 

 Acatithephyra, known at that time, by the very thin and membranaceous integument and 

 the very short rostrum, which no doubt has led to the establishment of this new genus. 

 Nowadays, however, already three species of Acanthephyra are known in which the integument 

 is similarly soft, thin and membranaceous and in which the rostrum is short, viz. Acanth. brevi- 

 rostris S. I. Smith, Acanth. rostrata (Bate) and the interesting Acanth. Sidogac: the name of 

 Meningodora may therefore be retained for that small section of Acanthephyra, in which those 

 characters occur. In the Table of Species oi Acanthephyra (Stanley Kemp, in: "Fisheries, Ireland, 

 Sci. Invest., 1905, I., [1906], p. 23") Acanth. mollis must be classed in the third Section C, 

 being related to Acanth. Batei. 



Eight species of Hoplophoridae have been obtained by this expedition, they belong to 



SIBOGA-EXPEUITIE XX.XlXa'. 6 



