The unclued lights are of a specific kind.
 

Across

 
11    Top flier backs help for sloth (6)
12    Birds on the barriers (5)
14    Mayfly larva on cobras, dead (5)
15    The head that’s characteristic of the Russian Church (5)
17    Lay claim to 32s somehow (6)
19    Eric needs new place to stay (9)
21    Caught fish, mushy peas and wine? (7)
24    Short Celt, retired keeper, in a 2-2 match? (9, two words)
26    Prince, lively, talking idly (9)
30    Spanish muleteer, backward, out east, love (7)
31    Churchmen waving signal around prison (9)
33    Karnataka, formerly, note, has blooming interior, to the east (6)
36    Circle’s grim repute (5)
37    Feminist writer Caitlin — could be Norma (5)
38    Fleecy head-wrap from ancient African region (5)
39    What you may do after bad ’arvest? (6)
40    Would it reveal gossip about state? (7)
41    Mouths greeting in Gaelic, endlessly (7)
 

Down

 
1    Framework of vehicle receiving investigation (7)
2    Small organ in sculpture galleries (5)
3    Heartless girl will make changes (4)
4    Erin and Italy represented in one dimension (9)
5    With colours of the rainbow — touch of indigo is surrounded by another (6)
7    Decree, alternatively, stoop, we hear (6)
8    O’Neill dies mixing resin (10, two words)
9    They transfer property breaking iron seal (8)
10    Two lads showing injured pride (6)
22    Mean-spirited wretches from Sancerre crashed around junction (9)
23    Spends time idly at lodges (8, two words)
27    Soap’s hollows (7)
28    Pacific islands accepting small savoury (6)
29    Jewel thief is a potential killer (6, two words)
30    Jacket Romeo hides in a tree (6)
32    39 — 5 for the bird (5)
35    Rugs with fringes of ruby across (4)
 
A first prize of £30 for the first correct solution opened on 18 August. There are two runners-up prizes of £20. (UK solvers can choose to receive the latest edition of the Chambers Dictionary instead of cash — circle the word ‘Dictionary’.) Entries to: Crossword 2173, The Spectator, 22 Old Queen Street, London SW1H 9HP. Please allow six weeks for prize delivery.