In UK items like the gas bubble holes are called "way up structures" which is charmingly direct. Arthur's Seat Edinburgh is a similar classroom in igneous intrusions, where Charles Darwin was taught some wrong "Neptunian" geology (the dolerite was supposedly crystallised out of some primordial ocean. When it rather clearly wasn't)
Cannot resist offering this link to a photo of a statue of Thomas Francis Meagher in his role as Union General in charge of the New York Irish Brigade, name sake of Meagher County for which the Meagher Formation is named. Hope you don't find this too unwieldy https://images.search.yahoo.com/yhs/view;_ylt=AwrijXeV.45mKJwkkEo2nIlQ;_ylu=c2VjA3NyBHNsawNpbWcEb2lkAzZmYjhmNzkyZTEwMGYxNzY4MDIyMzBkNzk0MmRjZjk1BGdwb3MDNARpdANiaW5n?back=https%3A%2F%2Fimages.search.yahoo.com%2Fyhs%2Fsearch%3Fp%3DMeagher%2Bstatue%26ei%3DUTF-8%26type%3Dud-c-us--s-p-cvtyqrye--exp-none--subid-none%26fr%3Dyhs-infospace-047%26hsimp%3Dyhs-047%26hspart%3Dinfospace%26param1%3Dzmffime51eteka034eyyn87j%26tab%3Dorganic%26ri%3D4&w=1300&h=955&imgurl=c8.alamy.com%2Fcomp%2FCW10PE%2Fthomas-francis-meagher-statue-montana-state-capitol-building-helena-CW10PE.jpg&rurl=https%3A%2F%2Fwww.alamy.com%2Fstock-photo-thomas-francis-meagher-statue-montana-state-capitol-building-helena-49809718.html&size=218.4KB&p=Meagher+statue&oid=6fb8f792e100f176802230d7942dcf95&fr2=&fr=yhs-infospace-047&tt=Thomas+Francis+Meagher+Statue+Montana+State+Capitol+Building+Helena+MT+...&b=0&ni=90&no=4&ts=&tab=organic&sigr=U.rrHLNnbasN&sigb=vGK_KOzIkIMm&sigi=LIjXVz75Zr33&sigt=NAtTdtBjxdSN&.crumb=wUk13GGL5Rx&fr=yhs-infospace-047&hsimp=yhs-047&hspart=infospace&type=ud-c-us--s-p-cvtyqrye--exp-none--subid-none¶m1=zmffime51eteka034eyyn87j
In UK items like the gas bubble holes are called "way up structures" which is charmingly direct. Arthur's Seat Edinburgh is a similar classroom in igneous intrusions, where Charles Darwin was taught some wrong "Neptunian" geology (the dolerite was supposedly crystallised out of some primordial ocean. When it rather clearly wasn't)
They are also called geopetal structures, from Latin petare, to aim or point. "Way up structure" is wonderfully clear in what it means!