Given a text passage, you need to generate a suitable title as the output. The output title should be one of the words/phrases used in the passage and must be no longer than five words. 

[EX Q]: Paragraph:    The revival of the observatory on the Gregorian Tower was initiated by the Barnabite Francesco Denza with the approval of Pope Leo XIII . High quality instruments were procured , partly with generous donations from Hicks of London , and the automatic recording instruments were procured from Richard in Paris . A four @-@ inch equatorial , a three @-@ inch transit instrument , and four pendulum clocks with two chronometers , were also procured from the observatory at Modena . In 1888 , the gift of a 16 inch long telescope to Pope Leo XIII , became a part of the observatory . Father Denza joined the observatory in 1889 after it was upgraded with more modern instruments . The same year , a second tower was built some 400 metres ( 1 @,@ 300 ft ) away from the main Gregorian Tower , overlooking the Vatican Gardens behind St. Peter 's Basilica on the south @-@ west border . It was built to a diameter of 17 metres ( 56 ft ) with a lower wall thickness of 4 @.@ 5 metres ( 15 ft ) , which could bear the load of a 13 inch photographic refractor , newly procured from Paris . Augustinian Father Rodriguez was the expert meteorologist who held the post of director from 1898 to 1905 . In 1891 , Pope Leo XIII , promulgating the motu proprio Ut mysticam , designated the second tower as the seat of the newly established Vatican Observatory , a decision which required altering the roof to provide a flat terrace for astronomical observations .   Question: what is the suitable title of the passage ?
[EX A]:  Third stage

[EX Q]: Paragraph:    Note : Pos 
 Question: what is the suitable title of the passage ?
[EX A]:  Skaters

[EX Q]: Paragraph:    The first scientific description of the plain maskray was authored by Commonwealth Scientific and Industrial Research Organisation ( CSIRO ) researcher Peter Last in a 1987 issue of Memoirs of the National Museum of Victoria . The specific name annotatus comes from the Latin an ( " not " ) and notatus ( " marked " ) , and refers to the ray 's coloration . The holotype is a male 21 @.@ 2 cm ( 8 @.@ 3 in ) across , caught off Western Australia ; several paratypes were also designated . Last tentatively placed the species in the genus Dasyatis , noting that it belonged to the " maskray " species group that also included the bluespotted stingray ( then Dasyatis kuhlii ) . In 2008 , Last and William White elevated the kuhlii group to the rank of full genus as Neotrygon , on the basis of morphological and molecular phylogenetic evidence . 
 In a 2012 phylogenetic analysis based on mitochondrial and nuclear DNA , the plain maskray and the Ningaloo maskray ( N. ningalooensis ) were found to be the most basal members of Neotrygon . The divergence of the N. annotata lineage was estimated to have occurred ~ 54 Ma . Furthermore , the individuals sequenced in the study sorted into two genetically distinct clades , suggesting that N. annotata is a cryptic species complex . The two putative species were estimated to have diverged ~ 4 @.@ 9 Ma ; the precipitating event was likely the splitting of the ancestral population by coastline changes .   Question: what is the suitable title of the passage ?
[EX A]:
Taxonomy and phylogeny