Sept., 1912.] Matheson : Haliplid.e of North America. 191 



(8) In Haliplus the air supply is probably obtained through the 

 two thoracic and seven abdominal spiracles. In Pcltodytcs there are 

 no spiracles and the air supply is obtained by means of numerous, 

 long, jointed, tracheated spines. 



(9) The larval life lasts but a short time (three to four weeks). 

 Pupation takes place in the soil in a small earthen chamber. The 

 pupal life lasts about three weeks. 



(10) There is probably more than one brood a season. 



Bibliography. 



AuBE, Charles (1838). Species generales des Coleopteres de la collection de 



M. le Comte Dejean, Tome VI, pp. 2-39. 

 Branden, C. van den (1884). Catalogues des Coleopteres Carnassiers Aquati- 



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 Blatchley, W. S. (1910). Coleoptera or Beetles of Indiana. Bull. I. Dept. 



Geology and Natural Resources, pp. 200-204. 

 Erichson, W. F. (1832). Genera Dyticeorum. Dissert. Inaug. Berlin, Hold., 



pp. 46-48. 

 Fall, H. C. (1901). List of the Coleoptera of Southern California with Notes 



on the Habits and Distribution and Descriptions of New Species. Occa- 

 sional papers of the California Academy of Sciences, Vol. VIII, pp. 51-52. 

 Ganglbauer, L. Die Kafer von Mitteleuropa. Erster Band, pp. 422-433. 

 Gemminger and Harold (1868). Catalogus Coleopterorum, II, pp. 425-427. 

 Needham, J. G. and Williamson, Helen V. (1907). Observations on the 



Natural History of the Diving Beetles. Amer. Nat., XLI, pp. 477-494. 

 Regimbart, M. (1878). £tude sur la classification des Dytiscides. Ann. Soc. 



Ent. Fr., VII (5), pp. 447-466. 

 Schiodte, J. C. (1861-1872). De Metamorphosi Eleutheratorum. Forste Bind, 



Pars II, pp. 70-74, Tab. VIII, Fig. 1-18 (1864); Pars VI, pp. 176-177; 



203-207, Tab. VIII, Fig. 1-13 (1872). 

 Thomson, C. G. (1857). Skandinaviens Coleoptera Synoptiskt bearbetade, 



Lund. 

 Wickham, H. F. (1895). The Coleoptera of Canada. VIII. The Haliplid^ 



and Dytiscidae of Canada. Canadian Ent., XXVII, pp. 69-70. 



Explan.\tion of Abbreviations Used. 



a. Muscle of maxilla. mc. Middle coxa. 



ac. Antecoxal piece. mp. Maxillary palpi. 



c. Coxa. ms. Mesosternum. 



ca. Cardo. mt. Metasternum. 



e Eye. pc. Posterior coxa. 



em. Epimeron pg. Palpiger. 



