Zoological Society. S$So 



is not sufficiently described by M. Gucrin to enable me to satisfac- 

 torily ascertain its exact structure. 



3. Chirocephalus claviger, Fischer. Antennis inferioribus 

 maris validis, articulo basalt magno, terminal) parvo, ad basin 

 denfato, ad apicem clavato ; antennis superioribus quadri-arti- 

 cufatis; front e rotundato. 



Long. 8-10 lin. 



Branchipus claviger, Seb. Fischer, Middendorff's Sibirische R«ise, 

 ii. Wirbellose, 141). t. 7. f. 1-11 (1851). 



Hab. In fluvio Taimyr, in Siberia ; Middendorff. 



This species, which is about 8 or 10 lines long, was discovered by 

 M. Middendorff in a pool of water by the river Taimyr in Siberia. 

 The inferior antennae of the male are strong organs ; the basal joint 

 being stout and fleshy and the terminal narrow, provided with about 

 a dozen small teeth at its base, and ending in a club-shaped extre- 

 mity. The digitiform appendages are more numerous apparently 

 than in C. diaphanus. They arise from the extremity of the long 

 riband-like appendage, instead of from its base, and each of them 

 has several teeth on the sides and apex. In the female these an- 

 tennae are small, narrow and sharp-pointed. The superior antennae 

 are divided into four articulations. 



4. Chirocephalus birostrattjs, Fischer. Antennis inferio- 

 ribns maris validis, articulo basalt magno, terminali mediocri, 

 prope basin p>rocessu elongato armato, ad apicem uncinato. 



Long. 10-12 lin. 



Branchipus birostratus, Seb. Fischer, Middendorff's Sibirische 

 Reise, ii. t. 7. f. 12-10 (1851). 



Hab. Prope urbem " Charkow " in Russia , Fischer. 



This species is about 10 or 12 lines long, and was found by 

 Fischer in the neighbourhood of the town of Charkow, in Russia. 

 The inferior antennae of the male are strong organs, the basal joint 

 stout and fleshy, the terminal of moderate size, having, springing 

 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 like process appears similar to that of C. diaphanus. 



5. Chirocephalus Middendorffianus, Fischer. Antennis 

 inferioribus maris validis, articulo basali magno, longissimo, 

 numerose denfato, terminali cylindrico, acuto ; antennis supe- 

 rioribus quadri-articulatis ; front e quadrangulari. 



Long. 7- lin. 



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

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



Hab. In fluviis " 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 



