S. 1. S)i}!f/i—H<(rh/ Stdf/ex of Ilippa talpokht. :UM 



beneath tlio surluce. Occasionally, however, they are found swinnnin^- 

 about in ])ools left by the tide, and they undoubtedly, when undis- 

 turbed, sometimes come out and swim in the same way along the 

 shore, though they probably never venture far from tlie bottom. 



When first placed in an aquarium with a few inches of sand at the 

 bottom, they invariably ])lunged at once entirely beneath the sand, 

 but, after a few moments of quiet, usually worked themselves gradually 

 towards the surface, resting in a nearly perpendicular position with 

 just the tips of the aiitennuhe and eyes at the surface, while the ex- 

 cui'rent water from the branchiae formed a small opening and a 

 slightly boiling motion in the sand. Occasionally, when entirely 

 undisturbed, they would suddenly leave the sand and swdni rapidly 

 round the top of the aquarium for a moment and then dive suddenly 

 to the bottom and bury themselves in the sand. In swimming, as 

 well as in burrowing, the telson was carried appressed to the sternum 

 and they invariably moved backward, the motion being ap|)arently 

 produced by the appendages of the sixth abdominal segment and the 

 anterior thoracic legs, while the latter served also as steering organs. 



During all the ordinary motions of swimming and burrowing, I 

 have never seen the antenna^ extruded, although the peculiar arrange- 

 ment of the peduncular segments and their complex system of muscles 

 are apparently specially adapted for extending and withdrawing 

 these beautiful organs. When the animals are thrown into alcohol 

 however, the antennre are sometimes thrown out convulsively and 

 then immediately retracted. In life the antennae are most of the 

 time held in the position in which they are usually found in alcoholic 

 specimens, that is, between the second and external maxillipeds, with 

 the peduncles crossed in front, and the flagella curved down and 

 entirely round the mouth so that their dense armament of sette all 

 project inward. When extruded, the distal segments of the peduncle 

 are revolved half way round on the proximal ones, so as to carry the 

 whole appendage to its own side of the animal and throw the curve 

 of the flagellum into a reversed position. Judging from the pecul- 

 iarly armed setae, of the flagella, one of the principal offices of the 

 antenna? is the removal of parasitic growths and all other foreign 

 substances from the appendages of the anterior portion of the animal. 



The mouth parts of the adult are not adapted for ordinary prehen- 

 sion or mastication, but I am unable to make any positive statement 

 in regard to the food of these animals. In all specimens examined 

 the alimentary canal was filled with tine sand which seemed to be 

 nearly free irom animal or vegetable matter. The material from the 



