128 DR. n. J. HANSEN ON THE INGOLFTELLTDiE, 



Ingolfiella is clearly distmguisliecl from all Ampliipo'la 

 Gammarina and Caprellina {sens. SteUing) hy at least four 

 characters. Tioo of these are of very high raiiTc, viz. the complete 

 separation of eye-loles from the head and the structure of the 

 pleopods ; the tioo other characters are less important, viz. the 

 elongate styliform shape of the molar process of the mandibles, 

 and tie structure of the first two pairs of prehensile hands, in 

 which the fifth joint is developed as a hand and the two distal 

 joints, together with the real claiv, are so completely claw-shaped 

 that a similar structure has not heen observed in any other 

 form. — Two other characters seldom met witli iu auy other 

 Amphipod, viz., the relative development of the joints of the 

 palp of the maxillulse, and the structure of the seventh joint with 

 its claw of the third and fourth pairs of thoracic legs, have not 

 been deemed worthy of enumeration together with the four 

 characters above mentioned. 



Ingolfiella agrees with the family Caprellidss — of the tribe 

 Caprellina — in some features : the body is filiform, without 

 " epimeral " plates ; the first thoracic segment is more broadly 

 and more closely connected with the head than with the 

 following segment. But from the tribe Caprellina, Ingolfiella 

 is separated not only by the four characters distinguishing it 

 from all Amphipoda, but also by some other features to be 

 enumerated. The antennulae have an accessory flagellum which 

 is absent in the Caprellina ; the abdomen, which is only a little 

 shorter than the thorax, has the full number of well-defined 

 segments and six pairs of appendages ; the seventh joint and 

 the claw are very sharply separated on the thu'd and fourth 

 pairs of thoracic legs ; branchiae are present on the third, fourth, 

 and fifth pairs of legs, but iu the Caprellina branchiae are always 

 wanting on the fifth pair, furthermore, Ingolfiella differs from 

 the family Caprellidae in some additional features : in the palp 

 of the maxillulae the fii'st joint is unusually long, longer than 

 the second, while in the Caprelhdse the second joint is very 

 much longer than the first; the maxillipeds have no lobe from the 

 third joint and their second joints are not coalesced in the median 

 line, but in the Caprellidse at least the basal parts of the second 

 joints are coalesced and the third joint has a well-developed lobe ; 

 the first prehensile hand is a little larger than the second, and 

 of both pairs the hand itself is the fifth joint, but in the 

 Caprellidse the first hand is much smaller than the second and 



