5169915546

23

zen spccimcns is avaiIab!e Iherc is not much difficulty in dcter-mining G. nałałor L. but single separated from

l i

- *

; of large size cannot be easily of G. subsłriałus var. fowleri O.-C. This

variety is in my very

experience smooth and has no

fine puncturation on the thorax, while there is usually, if not always, a fine puncturation of the pronotum in G. natator L, although it is sometimes difficult to see,

Duli black specimens of G. natator L. are not uncommon, The se usually ha\e a well marked fine puncturation, although this is not invariable. A few indhiduals are very duli and have the surface of the elytra somewhat crenulated, thus approa-ching the condition found in G. substriatus var. schatzmayri

Ochs,

Gyrinus substriatus Steph, 1828

Average size:

Largest:

Smallest:

5,6

6,15

x

A

3.0

3.4 mm;

5,00 x 2,75 mm;

6,30 x 3,55 mm,

6.85    x 3,80 mm,

5.85    x 3,25 mm,

L o c a 1 i t i e s:

var, siculus Reg.: Lakę Wigry, VI,1931, 1 c:A 1 L ;

near Wigry, Pond Nr, 2, V,1931_f 12 Pond Nr, 4, V, 1931, 11 cA 6    .

16    . Pond Nr, 3, V,1931, 18 cA 5

"i

Ponc! Nr. 2, V[. 1931, 19 c\ 17

, Pond

Nr, 3, VI, 1931, 16

7

Pond Nr, 4, VI, 1931, 28 A 23

Pond Nr, 5,

A b _;; var. schatzmayri Ochs: near Wigry, Pond Nr, 3, V. 1931, 3    ', Pond Nr, 4, V, 1931, 1 C, Pond

Nr, 3, VI, 1931, 1    .

Lwów, 2, IX. 1916, 1    ;

p, Kałusz, 8, IX, 1919, 2

2

VI. 1931, 4

5

Pond Nr, 6, VI, 1931, 13

substriatus near var, siculus or typical; Dublany p, ; Pełkinie p, Jarosław, 17, VIII, 1919, 1 A Kopanki

: Majerówka p, Lwów, 31, VIII. 1921, 1 ; Wołkowce n. I)n. p, Borszc/nw, hrnok in valley, 18, VII, 1922, 3

1

i

i

A A

; Swarzewo p, Puck, 22. V11J, 1022, 2

k

3

; Sobolewo p, Suwałki 19,

IX, 1922, 4 „A 4 _: ; Filipkowce p, Borszczów, 7, VII, 1923, 4 ce p, Horodenka, 13, VII, 1923, 2

1 y ; Strzel-

; Struszta p. Brasław, 14, VIII. 1924, 4 cA 5 Q; Białowieża rezerwat, 26. VIII, 1924, 1 _A 1 A ab, fowleri 0,-C,:

Kopanki p, Kałusz 7-8, IX, 1916, 1

2

Zaleszczyki, 9, VII 1923, 2

Białowieża rezerwat, 26, VIII, 1924, 4    ; var, siculus Reg,: Borszczów, brook

in wood, 15, VII. 1922, 4

Olch owiec n, Dn, p, Borszczów, brook, 16. VII,

1922, 2 cN 3 Q; Obieżowa near Zaleszczyki 11, VIII, 1925, 2 9'

Moderately convex; apex of elytra roundly truncated; pronotum and elytra rarely crenulated and with dense fine puncturation (var. schatzmayri Ochs) sometimes with a dense but subdelete fine puncturation (var. siculus Reg), sometimes smooth

*