25 



from near its base, a somewhat elongated process armed with sharp 

 teeth at its extremity, and ending in a sort of hooked point. The 

 riband-hke process appears similar to that of C. diaphanus. 



5. Chirocephalus Middendorffianus, Fischer. Antennis 

 inferioribus maris validis, articulo basali magno, longissimo, 

 numerose dentato, terminali cylindrico, acuto ; antennis supe- 

 rioribus quadri-articulatis ; fronte quadrangulari. 



Long. 1-1 lin. 



Branchipus Middendorffianus, Seb. Fischer, Middendorff's Sibi- 

 rische Reise, ii. 153. t. 7. f.17-23 (1851). 



Hab. In flmais "Taimyr et Boganida " in Siberia; prope "Tri- 

 Ostrowa " in Lapponia ; Middendorff. 



This species, which is only from 7 to 9 lines in length, was found 

 by Middendorff in pools on the banks of the rivers Taimyr and Bo- 

 ganida in Siberia, and in Lapland near Tri-Ostrowa. The inferior 

 antennae in the male are stout organs, the basal joint being very long 

 and fleshy and armed along the inner edge with a long row of many 

 teeth, the terminal being cylindrical in shape and pointed at the ex- 

 tremity. The superior antennae are four-jointed, and the front of 

 the head is of a quadrangular shape. The ovarian sac in the fe- 

 male is long and rather slender, and appears to be notched at the 

 base. 



Genus Artemia, Leach. 



Corpus molle, gracile ; segmentum caudate pinnis nullis instruc- 

 tum ; pedes undecim ; antennce inferiores maris magna, biarticu- 

 latce, compresses, appendicibus nidlis armatce. 



Syn. Cancer, Linnaeus. — Gammarus, Fabricius. — Eulimene, La- 

 treille et auctorum. — Artemia, Leach et auctorum. — Branchipus, 

 Latreille, Fischer, &c. — Artemisus, Lamarck. — Artemis, Thompson. 



The body in this genus consists of the same number of segments 

 as in the three preceding, is soft and without covering, but is more 

 slender in shape, and has the caudal segment simply bilobed at the 

 extremity, instead of being armed with two large plumose fins. The 

 inferior antennae in the male are large, flat-shaped, broad, and di- 

 vided into two articulations. The basal joint has neither the antenni- 

 form appendage of Branchipus and Streptocephalus, nor the compli- 

 cated digitiform and fan-shaped apparatus of Chirocephalus. They 

 inhabit salt water, frequently even in water which is very highly 

 charged with salt. They swim upon their backs. 



The genus Eulimene was founded by Latreille in 1817i in Cuv. 

 Regn. An. 1st edit. iii. 68; that of Artemia by Leach in 1819, in 

 the Diet. Sc. Nat. xiv. The term Eulimene, however, had been pre- 

 viously used by Peron for a genus of Acalepha, and though the name 

 Artemia is liable to objections from its construction (Artemia for 

 Artemis), I prefer adopting it to burdening the nomenclature with 

 another synonym. 



Five species have been described. 



1. Artemia salina, Leach. Antennis inferioribus maris validis. 



