a base mounted on {TAIL ~ a bottom} of {HEAD ~ said housing} and provided with a plurality of tubular portions thereon 
a base mounted on { TAIL ~ a bottom } of { HEAD ~ said housing } and provided with a plurality of tubular portions thereon
OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH