Supter with acc

[Constantinus Philo]

According to Ernout/Thomas supter may take acc even without motion, this is unlike what English grammars of Roby, Gildersleeve etc say. I think Lucretius is a good example to corroborate the French view:
Aeneadum genetrix, hominum divomque voluptas,
alma Venus, caeli subter labentia signa
quae mare navigerum, quae terras frugiferentis
concelebras...- the meaning is where but not whither.

[mwh]

But there is motion. Just as the constellations slide over the earth and ocean (from a terrestrial viewpoint), so earth and ocean correspondingly slide beneath them. Nothing stands still in Lucretius. Besides, this is a highly poetic passage.

[Constantinus Philo]

so in poetry one might come across supter with acc without motion if i understand what you are saying

[mwh]

No you have not understood. In the Lucretius there is motion, as I explicitly said and explained.

[Constantinus Philo]

But the verb concelebras answers the question where and not whither. Venus revives or whatever the land and the sea where? under the gliding constellations of the heaven. Or maybe what is meant is that Venus goes under the gliding constellations to visit land and sea reviving them.

[Callisper]

Who (=which grammar/piece of scholarship) says motion is relevant here?

[Constantinus Philo]

See Gildersleeve 418, 3a where he says that subter with acc is locally equal to sub (with acc I guess, but quite aenigmatically, he didn't specify). Roby explicitly says that subter with acc is used with verbs of motion answering the question whiter.
Ok I have checked Greenough also where he has subter togam - so, it would appear as if there is no need for motion, however there is motion in the context: manum subter togam exseruit ad mentem.

[mwh]

I find it more rewarding to read Latin than grammars.

supter: I think not only of Lucretius’ proemium but also of Catullus’ pathetic poem on the death of his brother, Cat.66: Troia Rhoeteo quem supter litore tellus, a line that Vergil would have been proud of. There supter is no different from sub, and the ablative is clearly what’s called for. But it’s true that subter with acc. is much commoner, even when it doesn’t seem to be directional. For questions like this the OLD is surely a sufficient resource.

[talus]

This post reviews some early grammars on the use of the preposition supter (subter) for position and motion with accusative.
Zumpt (1818) §295:
Zumpt defines subter as "under, beneath, is used with the accusative, whether it express being in or motion to a place; it rarely occurs with the ablative and is in general little used."
In §320 Zumpt gives an example from Cicero of a use of subter with accusative denoting position
Plato iram in pectore, cupiditatem subter praecordia locavit. [praecordia is used in the plural] Plato located ire in the breast, cupidity in the gut. [In that which is beneath, or "at the foot of," the diaphragm.]
C. D. Yonge translates this sentence as "placing desire under the præcordia."
Andrew P. Peabody translates this as "to desire, under the diaphragm."
The OLD for praecordia, defintion 1, uses the above sentence from Cicero to illustrate the meaning of praecordia as the "vitals."
Madvig (1844) §230:
Madvig writes that subter with ablative is used only in the poets.
Kennedy (1872) §72:
Kennedy writes that subter signifies "extension under, generally governs Accusative, but sometimes in poetry an Ablative."
He does not remark on the suffix -ter but we can take the definition he gives as denoting something further than sub, as employing the demonstrative -ter to add something a bit deeper and/or farther in space than sub.
(A note on -ter. The suffix -ter is used in three ways: 1) to form adverbs from 3rd declension adjectives such as diligens, diligenter; 2) in words of contrast such as dexter:sinister; and 3) as an emphatic or hyberbolic where -ter, literally meaning "thrice," is to be read as "very much" or "highly." The OLD writes that -ter in subter is in the category of -ter in words such as praeter and propter. Lewis and Short write in their definition of praeter: "adv. and prep. prae, with the demonstrative suffix ter, as in inter, subter, propter, signifies motion." But in the literature it is not always apparent that subter is emphatic or implies extension compared to sub when subter is used for position.)
Roby (1862, expanded 1872):
Roby §2124ff writes that subter can be used for both position and motion.
He gives three examples of the use of subter, all with the accusative. Two examples are of subter as position.
The third example, at first glance, might appear to be a subter of motion since the sentence is about motion.
"He rides on his swift horse at the foot of the wall [subter murum] of the enemy to his cohorts."
The galloping horse is in motion along the wall but its position at the foot of the wall is constant. So this is also a subter of position, not motion.
For subter as motion, the OLD for subter as a preposition, definition 2, states that the following passage from the Aeneid expresses motion, not position.
The Aeneid 3.695
Alpheum...occultas egisse vias subter mare [ago, agere, egi, actus] the river Alpheus...pursued secret paths down under the sea
Two translators, Dryden and Fitzgerald, translate subter in this passage from the Aeneid as position, not motion.
Fagles translates subter as motion.
Sticking with the Aeneid we find a few other uses of subter as position or adverb and one as motion.
The Aeneid 8.366-367
angusti subter fastigia tecti ingentem Aenean duxit he led Aeneas, a fellow greatly to be reckoned with, beneath the narrow, peaked covering
In both of these passages we can detect in subter "motion under and through" and so we can read Kennedy's meaning of "extension."
A point of interest about these two sole uses in the Aeneid of subter of motion is that both are also found in
subter+verb compound verbs of motions. Roby §2142 lists six subter compound verbs of motion,
among them are subteractus, driven beneath, and subterducere, withdraw. Roby characterises these
subter compounds as ones in which the preposition is loosely bound to its verb, subter and verb
used just as well separately as they are in compound, that is, subter+ducere or ducere...subter. However in the real world of literature it looks like most authors either never had such subter compounds in their ready vocabulary or found subter+verb compounds to be infelicitous Latin.)
(For discussions on the composition of compounds tight and loose and on the meaning of what Roby refers to as "no clear mark of composition" in these subter compounds see Roby §979, in Vol 1, the section titled, "Composition;" Gildersleeve and Lodge §193ff; Alen and Greenough §227ff; Gildersleeve's article in The American Journal of Philology, Vol XXV, 1904.)

[Barry Hofstetter]

I find it more rewarding to read Latin than grammars.

supter: I think not only of Lucretius’ proemium but also of Catullus’ pathetic poem on the death of his brother, Cat.66: Troia Rhoeteo quem supter litore tellus, a line that Vergil would have been proud of. There supter is no different from sub, and the ablative is clearly what’s called for. But it’s true that subter with acc. is much commoner, even when it doesn’t seem to be directional. For questions like this the OLD is surely a sufficient resource.

subter2 prep. Also supter. [as subter1] CONSTRUCTION: usu. with accusative, expr. both direction or position (sometimes following its noun); expr. position, also with ablative (CATUL. 65.7; VERG. A. 9.514).

Glare, P. G. W. (Ed.). (2012). Oxford Latin Dictionary (Second Edition, Vol. I & II). Oxford: Oxford University Press.