ZOOLOGY. 441 



white ant, have been described, from the carboniferous for- 

 mation of Illinois, by Mr. Scudder. 



A synopsis of the North American species of Alpheus, a 

 genus of shrimps, by J. S. Kingsley, appears in the Bulletin 

 of Hayden's United States Geological Survey. The common 

 species on the coast of Florida Alphem minus lives in 

 great abundance in the larger openings (oscula) of sponges. 

 This and another common Floridian form Alpheus hetero- 

 chelis (Say) occur at Panama and at Realejo, West Nica- 

 ragua. These, with Alpheus trcmsverso-dactylus (Kingsley), 

 add three more to the small list of Crustacea common to the 

 Atlantic and Pacific coasts of Central America. 



In this connection it is interesting to notice the discovery 

 of Branchipus (or Chirocephalus) in a fossil state, associated 

 with Archceoniscus, and with numerous insect remains, in the 

 eocene fresh-water limestone of the Isle of Wight, by Henry 

 Woodward. Of the Branchipus, both sexes are beautifully 

 preserved, the males showing their large clasping antenna), 

 and the females their egg-pouches, with large and very dis- 

 tinct disk-like bodies representing the compressed eggs. It 

 is called Branchipodites vectensis. 



Professor Pavesi contributes to the Bulletin of the Ento- 

 mological Society of Italy an article on the pelagic fauna 

 of the Italian lakes. The fauna consists chiefly of cladoce- 

 rous Crustacea of the genera Daphnia, Bythotrephes, Lepto- 

 dora, and Ileterocope. 



The Nebaliadoe, represented by the existing genus JYeba- 

 lia, have generally been considered to form a family of Phyl- 

 lopod Crustacea. MetschnikofF, who studied the embryology 

 of JVebalia, considered it to be a "Phyllopodiform Decapod." 

 Besides, however, the resemblance to the Decapods, there is 

 also a combination of Copepod and Phyllopod characteris- 

 tics. The type is an instance of a generalized one, and is of 

 high antiquity, having been ushered in during the earliest 

 Silurian period, when there were, if we regard the relative 

 size of most Crustacea, and especially of living JVebalia?, gi- 

 gantic forms. Such was JDithyrocaris, which must have been 

 over a foot long, the carapace being seven inches long. The 

 modern JVebalia is small about half an inch in length with 

 the bod}'' compressed, and the carapace bivalved, as in Lim- 

 riadia, one of the genuine Phyllopods. There is a large ros- 



T2 



