y 



No. 21 ] FIFTH BIENNIAL REPORT 15 



tion: by Wilton Everett Britton. Part II. The Euplexoptera 

 and Orthoptera of Connecticut: by Benjamin Hovey Walden. 



17. Fourth Biennial Report of the Commissioners of the 

 State Geological and Natural History Survey, 1909- 1910. 



18. Triassic Fishes of Connecticut: by Charles Rochester 

 Eastman. 



19. Echinoderms of Connecticut: by Wesley Roscoe Coe. 



Four of these, viz. ? Bulletins 13, 16, 18, and 19, have been 

 published since the last biennial report. 



Bulletin 13, on the Lithology of Connecticut, includes a gen- 

 eral introduction ta lithology by Professor Barrell, of Yale Uni- 

 versity, and a special description of forty-one typical rocks from 

 Connecticut localities by Dr. Loughlin, of Massachusetts Institute 

 of Technology. In the general part of the work, lithology is 

 treated in relation to mineralogy and dynamical geology, so that 

 the student may learn somewhat of the agencies by which the 

 different types of rocks are produced, as well as their composi- 

 tion and characteristic aspect. In both the general and the 

 special part of the work attention is given chiefly to those charac- 

 teristics of rocks which can be recognized by the naked eye or 

 by the simple microscope, with comparatively little reference to 

 the phenomena which can be observed only by the examination 

 of thin sections under the compound polarizing microscope. This 

 limitation in the treatment of the subject renders the work adapted 

 to the use of comparatively elementary students. The usefulness 

 of the work in the educational institutions of the state will be 

 greatly enhanced by suites of specimens of rocks from the typical 

 localities described in the special part of the paper, which have 

 been distributed to colleges, normal schools, high schools, and 

 academies in the state, on condition that the respective institutions 

 should pay the cost of transportation. Any suites of specimens 

 remaining in the possession of the Survey after such distribution 

 will be sold and the money paid into the treasury of the state. 



Bulletin 16, on the Insects of Connecticut, forms the begin- 

 ning of a series of papers on that class of animals, whose publica- 

 tion may be distributed through a considerable number of years. 

 It is needless to comment on the economic importance of the class 

 of insects, many insects being among the worst enemies of the 

 agriculturist, while others, insectivorous or parasitic in habit, 

 tend to hold in check the destroyers of agricultural products. 

 The various parts of the work will be written by specialists 

 on various groups, under the general direction of Doctor Britton, 

 Entomologist of the Connecticut Agricultural Experiment 

 Station. The present bulletin includes two parts of the proposed 

 work. Part I. gives a brief outline of the general characters of 

 insects and their relations to other allied groups of animals, the 



