158 OEO. H. HORN, M. D. 



body, ])rcf;eiit but little of special importance, excepting the large size 

 of the posterior coxtB, their contiguity on the median line, and the 

 straight line separating them from the metasternum. It is curious 

 that another error should have crept into the copied description of l^a- 

 cordaire,as he states that tliese coxic are not contiguous on the median 

 line of the body. 



There would seem to be but little doubt that this insect should oc- 

 cupy the systennitic position assigned it by Dr. Leconte. although two 

 eminent entomologists have, the one (Dr. Schauni) called it an aber- 

 rant Carabide, the otlier (Prof. J^acordaire) assigned it a position 

 among the Dytiscidtw, in a subfamily of equal value to Haliplid;^ and 

 Pelobiidas. Doth opinions appear untenable by a review of the cha- 

 racters above given. 



With the DytiscidiB, Ainphizou lias but little in common, excepting 

 the large size of the posterior coxte. The parts of the mouth, as stated 

 by Schauin, have but little analogy to those of I)ytiscid;x). The broad 

 posterior coxte separate it very easily from the Carabides, while at the 

 same time, they are bounded anttn'iorly by a straight line, and cut ott" 

 entirely the metasternum from the abdomen. It is not, however, on 

 one character that the separation iA' Amphkun from the two named fam- 

 ilies must depend. 'J'he whole conformation presents anomalies 

 found singly in aberrant members of either family; but that the con- 

 centration of so many should occur in one insect is remarkable. Either 

 this insect should link the two families into one, or it should form a 

 family apart. The latter course would, therefore, seem the more ra- 

 tictnal. 



Dr. Schaum has seen considerable resemblances to the Tenebrionidae 

 in its structure. There may be some resemblance in form (as to N)/c- 

 (fypetus) or even in its sculpture. Mc.trius has also been said to resem- 

 ble some of the same family. It is difficult, however, to perceive any 

 real structural similarities. 



The antennae do not resemble those of the Tenebrionidic as Schaum 

 insists. There is a total absence of pulicscence, sensitive pores and 

 spongy patches, such as are found on the terminal joints in that family. 

 Jlere the case is reversed and the terminal joints are entirely smooth 

 and glabrous. The similarity of the coxtxi, particularly the posterior, 

 to those of Tenfijria is not very evident. 



The sexual distinctions are not well marked, the female is broader 

 and rather more robust. 



