In the appended notes, Darkbloom explains: "p.9. All happy families etc: mistranslations of Russian classics are ridiculed here. The opening sentence of Tolstoy’s novel is turned inside out and Anna Arkadievna’s patronymic given an absurd masculine ending, while an incorrect feminine one is added to her surname*. ‘Mount Tabor’ and ‘Pontius’ allude to the transfigurations (Mr G. Steiner’s term, I believe) and betrayals to which great texts are subjected by pretentious and ignorant versionists.

Wikipedia offers Vladimir Nabokov's explanation about Karenin/Karenina: "In Russian, a surname ending in a consonant acquires a final 'a' (except for the cases of such names that cannot be declined) when designating a woman; but only when the reference is to a female stage performer should English feminise a Russian surname (following a French custom: la Pavlova, 'the Pavlova'). Ivanov's and Karenin's wives are Mrs Ivanov and Mrs Karenin in England and America—not 'Mrs Ivanova' or 'Mrs Karenina'." Lectures on Russian Literature. 1980,New York: Harvest. pp. 137

In ADA there is an exchange between Van and Greg, with a playful slip concerning Arkadievich: ‘I last saw you thirteen years ago, riding a black pony — no, a black Silentium. Bozhe moy!’ [ ] ]I have an appointment in a few minutes, alas. Za tvoyo zdorovie, Grigoriy Akimovich.’/ ‘Arkadievich,’ said Greg, who had let it pass once but now mechanically corrected Van./ ‘Ach yes! Stupid slip of the slovenly tongue. How is Arkadiy Grigorievich?’ (I couldn't get the point of this apparently deliberate "slip")

In fact, Van and Greg had met a long time ago at Ardis (with the exchanges about Mesopotamia and Biblical paradises) and - in the midst of the multiple entertainments at Ada's birthday picnic - there might have been a reference to Tolstoy's Anna Karenin (it's been brought up before, but the berries are distinct**). "Ada and Grace danced a Russian fling to the accompaniment of an ancient music box (which kept halting in mid-bar, as if recalling other shores, other, radial, waves); Lucette, one fist on her hip, sang a St Malô fisher-song; Greg put on his sister’s blue skirt, hat and glasses, all of which transformed him into a very sick, mentally retarded Grace; and Van walked on his hands."

Greg returns the next day to return Marina's lighter. ‘I ask myself who can that be,’ murmured Mlle Larivière from behind the samovar (which expressed fragments of its surroundings in demented fantasies of a primitive genre) as she slitted her eyes at a part of the drive visible between the pilasters of an open-work gallery. Van, lying prone behind Ada, lifted his eyes from his book (Ada’s copy of Atala). Answering to Marina's greetings Greg says "that both Aunt Ruth and Grace were laid up with acute indigestion — ‘not because of your wonderful sandwiches,’ he hastened to add, ‘but because of all those burnberries they picked in the bushes.’ "

Another interesting feature in the dancing-berry pickings is a samovar. It's suggested, at first, that the word sharovars "got garbled in the agent's aerocable" and its ressurgence, reflecting Mlle Larivière, returns to anamorphosis, with its garblings and distortions Burnberries might equally have resulted from a transformation of Tolstoy's original berries. However, Brian Boyd thinks otherwise.***

** - "In a splendid orchard several merry young gardeners wearing for some reason the garb of Georgian tribesmen were popping raspberries into their mouths, while several equally implausible servant girls in sharovars (somebody had goofed — the word ‘samovars’ may have got garbled in the agent’s aerocable) were busy plucking marshmallows and peanuts from the branches of fruit trees. At an invisible sign of Dionysian origin, they all plunged into the violent dance called kurva or ‘ribbon boule’ in the hilarious program whose howlers almost caused Veen (tingling, and light-loined, and with Prince N.’s rose-red banknote in his pocket) to fall from his seat."

*** - 90.04-07: Ruth and Grace . . . all those burnberries they picked in the bushes: Appears to echo Ophelia’s flower scene (cf. “‘Yes indeed,’ began Marina, ‘when I was playing Ophelia, the fact that I had once collected flowers—’ ‘Helped, no doubt,’ said Ada” [63]): “There’s rue for you, and here’s some for me; we may call it herb of grace a’ Sundays” (Hamlet 4.5.180-82). As recorded in the Hamlet Variorum (ed. Horace Howard Furness, 1877; rpt. New York: Dover, 1963), which Nabokov mined for chapter 7 of Bend Sinister, the great eighteenth-century Shakespeare editor George Steevens notes: “there is a quibble meant in this passage, ‘rue’ anciently signifying the same as ruth, i.e. sorrow.” Nabokov was fascinated by the flowers Ophelia picks (see his “The Art of Translation,” The New Republic, 4 August 1941, 160, and Bend Sinister 113-15, 118).
90.05-07: indigestion . . . those burnberries they picked in the bushes: As if they are heartburn-berries. See 85.03-04 for “an angry burnberry bush” by the picnic site. Ardeur 76: “ces baies de Bengale qu’elles ont ramassées dans les buissons” (“those Bengal berries they picked in the bushes ”), punning on “Baie de Bengale” (“Bay of Bengal”) and “feu de Bengale” (“ Bengal light, signal light, flare”).
90.06: burnberries: N1: “invented word.” Berries that grow by the “burn” or brook first mentioned, generically, at 82.01, then as a rill at the picnic site, 83.32, 266.14-15, 286.24 (“Burnberry Brook”). MOTIF: burn; burnberry.

btw: the burning bush must be an allusion to the biblical scene where God addresses Moses; a "ribbon boule" could indicate a twisted ribbon, like it happens in topology, with the Moebius band; Bengal lights appear in Details of a Sunset: "The last streetcar was disappearing in the mirrorlike murk of the street and, along the wire above it, a spark of Bengal light, crackling and quivering, sped into the distance like a blue star.".