110 ANNUAL REPORT. 



suggested by this bizarre creature is a peculiar burlesque on the elephant. It 

 requires favorable light and a high power to study the nature of the antennae. 

 The feet are apparently wider than in Daphnia. Under a favorable light, the 

 carapace is seen to be reticulated with hexagonal cells (at least near the edge) and 

 is covered, in some specimens at least, by exceedingly minute tubercles. The 

 motion is steady, progressive, and not saltatory, as in many Daphnice, which is 

 due (as in Lyncese) to the shortness of the antennae. The species from which 

 this description is drawn may be distinct from the longirostris of Baird, but on 

 comparing both alcoholic specimens and drawings made from Hving specimens, no 

 differences of importance were detected. The reticulated and tuberculated nature 

 of the shell may be a local variation, or may have easily escaped his notice. The 

 form of the shell demonstrably varies, and so probably does the number of appa- 

 rent joints to the superior antennse. The species was found in only one locality, 

 having been dipped with a bottle from the bottom through the ice. but the time 

 of collection is lost. Later, careful search was made during autumn, but no 

 specimens rewarded the pains. The markings, and jointing of the antennse 

 would make good tests for microscopes of moderate power, for such as are inter- 

 ested in this subject. 

 Habitat. — Johnson's lake, Minneapolis. 

 (See Plate XVII.) 



TRIBE III. GTPROIDEA. Dana. 



Characters. — Dana gives the following : " The Cyproidea differ from aU other 

 Crustacea except the Lernceoids [and Rotatorial in the absence 

 of the pairs of appendages belonging to all the normal cephalo- 

 thoracic segments posterior to the eighth, that is, to the six 

 posterior of these segments. The last two of these six pairs 

 are obsolete in all the Lophropoda; and in the Cyclopoidea and 

 Daphnioinea the first four of them are natatory and foliaceoua, 

 together with also another pair, next anterior in most species. 

 The pairs of appendages present in the Cyproidea posterior to 

 the mandibles, in number four pairs, are divided variously be- 

 tween mouth and legs." This tribe embraces two families, only 

 one of which is represented in our locality, and aside from the 

 general characters of the oceanic family we must confine ourselves 

 to the other. 



TAMiLY I. Cypridae. Dana. 



Characters. — Antennse of the second pair subterete, three to five-jointed. Man- 

 dibles two-branched, the main branch or body, denticulate at 

 the extremity, the minor branch, or palpus several-jointed, palpus 

 remote from the apex of the mandible; eyes with their pigments 

 united, minute, with spherical lenses. Feet either two or if 

 more, slender and pediform. 



SUB-FAMILY 1. CYPRIN2E. Dana. 



Bibliography. — Cypris, Mutter and others. 



Cyproides (in part) M. Edwards, Hist. Nat. Crust. 

 Cypridse (in part) Baird, Trans. Berw. Club, ii, 153. 



