Comb 27 may be flat, or it may form, as in FIG 10, a channel leading towards {HEAD ~ guide} 13, and the channel may decrease in {TAIL ~ cross section} towards guide 13 
Comb 27 may be flat , or it may form , as in FIG 10 , a channel leading towards { HEAD ~ guide } 13 , and the channel may decrease in { TAIL ~ cross section } towards guide 13
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH