ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 123 



tion of sessile barnacles in the United States National Museum — a report 

 which includes a splendidly illustrated monograph on the American 

 forms. 



Food of Pelagic Copepods.* — C. 0. Esterly has made some 

 experimental observations on the feeding habits and food of pelagic 

 copepods, with reference to the question of nutrition by organic 

 substances in solution in tlie water. Floating particles (grains of 

 carmine in the experiment) are carried towards the mouth by water 

 currents set up by the movements of the head appendages. The 

 particles are delinitely directed by means of the sides of a sort of trough 

 formed by the long bristles of the anterior maxiliped. These appendages 

 are stationary most of the time. A little pellet is formed, and is held 

 immediately behind the mouth and taken in when the oesophagus is 

 dilated. It is apparently not necessarily the ordinary movements of 

 locomotion that cause the formation of the pellets, since animals may be 

 kept for hours in water to which carmine has been added without 

 injestiug the particles, while in other cases the colour appears in the 

 intestinal tract in a few seconds. Diatoms are the organisms, the 

 remains of which appear most often, but in many cases the tracts are 

 empty or contain only bits of debris and more or less of a green mass. 

 The amount of food, as indicated by the intestinal contents, is 

 surprisingly small in most cases, and does not bear out the figures given 

 by Piitter. It is possible, however, that an important part of the food 

 consists of plankton organisms without shells, which leave no recognisable 

 remains, 



Macrothrix hirsuticornis in the Trentino.f — Marco De-Marchi 

 reports from Lake Fedaja the occurrence of this species of Daphnid, 

 estaljlished by Norman and Brady. This is the first strictly Italian 

 record, but the species has been collected in Alpine lakes by Imhof and 

 Stingeliu. It is a characteristic northern and Alpine species, but of 

 very noteworthy adaptability to other situations. A full description is 

 given. 



Revision of Cheirurinse.J — Donald C. Burton has made a revision 

 of this sul>family of Trilobites, and comes to the conclusion that the 

 beginning of the Ordovician was a period of great variation of some 

 primitive Cheirurid, and that the greater number of the genera are the 

 result of contemporaneous and rather rapid differentiation at that time. 



Annulata. 



Spawn of Spio martinensis Mesn.§ — F. Mesnil remarks on the 

 few cases in which the spawn of marine Polychasts is securely known. 

 That of Phyllodoce maculata is familiar ; that, of ScoIojjIos miilhri was 



* Univ. California Publications (Zool.) xvi. (1916) pp. 171-84 (2 figs.), 



t Rend. R. 1st. Lombarclo, xlix. (191G) pp. 525-41. 



X Washington Univ. Studies, iii. (1915) pp. 101-52 (25 figs.), 



§ Bull. Soc. Zool. France, xli. (1916) pp. 32-5 (1 fig.). 



