▁United ▁States ▁took ▁control ▁of ▁Puerto ▁Rico ▁from ▁Spain ▁in ▁the ▁after math ▁of ▁the ▁Spanish - American ▁War ▁under ▁the ▁terms ▁of ▁the ▁Tre aty ▁of ▁Paris ▁of ▁ 1 8 9 8 . ▁In ▁ 1 8 9 9 , ▁the ▁United ▁States ▁conducted ▁its ▁first ▁census ▁of ▁Puerto ▁Rico , ▁finding ▁that ▁the ▁population ▁of ▁Ca on illas ▁bar rio ▁was ▁ 2 , 3 7 8 . ▁ ▁See ▁also ▁▁ ▁List ▁of ▁communities ▁in ▁Puerto ▁Rico ▁ ▁References ▁ ▁External ▁links ▁ ▁Category : Bar rios ▁of ▁U tu ado , ▁Puerto ▁Rico <0x0A> </s> ▁Bac ill us ▁s elen it ire du c ens ▁is ▁a ▁b acter ium ▁first ▁isolated ▁from ▁Mon o ▁Lake , ▁California . ▁It ▁is ▁notable ▁for ▁resp iring ▁o xy an ions ▁of ▁selenium ▁and ▁ar sen ic . ▁It ▁is ▁sp ore - form ing , ▁rod - sh aped ▁and ▁alk ali ph ile , ▁its ▁type ▁stra in ▁being ▁M LS 1 0 . ▁ ▁References ▁ ▁Further ▁reading ▁St ale y , ▁James ▁T ., ▁et ▁al . ▁" Ber ge y ’ s ▁manual ▁of ▁system atic ▁b acter i ology , ▁vol . ▁ 3 ." Will iams ▁and ▁Wil kins , ▁Baltimore , ▁MD ▁( 1 9 8 9 ): ▁ 2 2 5 0 - 2 2 5 1 . ▁ ▁Ber keley , ▁Roger , ▁et ▁al ., ▁ed s . ▁App lications ▁and ▁system at ics ▁of ▁b ac ill us