NORTH AMERICAN COLEOPTEKA. 253 



cies the curve is better marked. In the i-elation of the last two 

 joints to each other in length our species of Cjnibiodyta are inter- 

 mediate between the two sections of Philydrus, that is to say, while 

 these joints are not equal in length as in Enochrus, the terminal joint 

 is so little shorter than the preceding that, without careful observa- 

 tion, they might be thought equal. 



In some of the species there is a faint indication of a carina at 

 the apex of the prosternum. The mesosternum is not laminate as 

 in Philydrus, but has in all our species a slightly elevated, transverse 

 ridge, placed directly in front of the intercoxal process of the meta- 

 sternum. This ridge affects three forms which give useful aid jn 

 separating the species. These forms are — straight and directly 

 transverse — , arcuate ■^, or elevated at middle at an angle so that 

 when viewed from behind it is in the form of A with a little broader 

 angle. The last form seen in fraterculus and rotundas explains the 

 origin or meaning of the spine-like process seen in Helocombus. 



Contrary to the prevailing tendency in Philydrus the basal mar- 

 ginal line of the thorax is never pi'eseut. The large puncture near 

 the basal margin on each side is quite distinct in all the species, 

 although quite often very indistinct or wanting in some individuals. 



The general sculpture is the same as in Philydrus, and the same 

 series of coarse punctures on the head and thorax may be observed, 

 and in more than half of the species the elytra have distinct stria- 

 of punctures .varying in number from four entire striae to ten. The 

 rows of coarse punctures which have, apparently, no definite position 

 in Philydrus are here distinctly located on the alternate intervals 

 beginning with the third. 



In the species belonging to the Atlantic region proper the elytra 

 are not striate; they have, however, the coarse interstrial punctures, 

 which are approximated at apex forming a semblance to strii^e, but 

 no trouble need result if the student will compare these with the 

 punctures seen in the striate species. In my former descriptions this 

 error occurred, and it now gives me pleasure to correct it, and at the 

 same time give the proper interpretation of the sculpture. 



The underside of the body in sculpture and vestiture is the same 

 as in Philydrus, and the femora are finely punctured, pubescent and 

 opaque, except for a short distance near the tip. Sexual characters 

 have not been observed, and the males can be distinguished when the 

 organ is protruded, but apparently not otherwise. 



With two exce])tions the species are piceous black in color with 



