Centropyxis tabel – Microworld

Key to Centropyxis species

1	Shell in dorsal view circular or almost circular	2
–	Shell in dorsal view irregular due to various outgrows and invaginations	22
–	Shell in dorsal view elliptical or ovoid or resembling an 8	23

2	Shell with spines	3
–	Shell without spines	14

3	Edges of pseudostome with bridges or pilars between edge and dorsal part	4
–	Bridges absent	7

4	Diameter of the test 140-160 μm, in lateral view hemispherical	*C. hemisphaerica*
–	Diameter of the test does not exceed 100 μm	5

5	Shell in lateral view resembling a cap	6
–	Shell in lateral view in the form of a triangle	*C. decloitri*

6	Spines along the entire fundus	*C. hirsuta*
–	Spines only on the edge of the fundus	*C. cassis spinifera*

7	Pseudostome slightly eccentric	8
–	Pseudostome strongly eccentric	9

8	Shell 130 – 320 μm	*C. discoides*
–	Shell < 60 μm	*C. delicatula*

9	Pseudostome lobed	*C. spinosa*
–	Pseudostome not lobed, sometimes irregular in shape	10

10	Aperture lobed or crenate	*C. aculeata dentistoma*
–	Aperture not lobed or crenate	11

11	Spines very long, located not only on the fundus, but also on the visor	*C. discoides solari*
–	Spines only located on the fundus	12

12	Spines very long (40-60 μm)	*C. aculeata tropica*
–	Spines shorter	13

13	Diameter of the test 110-160 μm	C. aculeata
–	Diameter of the test 170-200 μm	*C. aculeata grandis*
–	Diameter of the test 80-90 μm	*C. aculeata minima*

14	Shell in lateral view flattened, rarely hemispherical	15
–	Shell in lateral view semi circular or slightly smaller or larger than hemispherical	16

15	Shell > 150 μm	*C. ecornis*
–	Shell < 60 μm	*C. delicatula*

16	Pseudostome very large (about half the diameter of the test), jagged	*C. latior*
–	Pseudostome not so big, its edge is not jagged	17

17	Shell with internal bridges	*C. laevigata*
–	Bridges absent	18

18	Pseudostome slightly eccentric	19
–	Pseudostome strongly eccentric	20

19	Diameter of the test 140-170 μm	*C. austriaca*
–	Diameter of test < 80 μm	*C. minuta*

20	Pseudostome small, close to the edge of the anterior part of the test	*C. plagiostoma*
	Pseudostome larger, halfway between center and edge	21

21	Diameter of test 100-140 μm	*C. orbicularis*
–	Diameter of test < 70 μm	*C. aerophila sphagnicola*

22	Shell in lateral view broad, pseudostome circular or elliptical, small, located on the ventral side of the test	*C. aurita*
–	Shell elongated elliptical in dorsal view, pseudostome crenate, subterminal, located at an angle of 45° to the longitudinal axis of the test	*C. chardeziella*

23	Shell in lateral view similar in shape to the figure-eight by narrowing between the pseudostome and fundus	24
–	Shell in dorsal view elliptical or ovate	30

24	Pseudostome subterminal, located at an angle of 30° with respect to the longitudinal axis of the test	*C. loffleri*
–	Pseudostome located on the ventral side of the test3	25

25	Shell without spines	26
–	Shell with spines	27

26	Main part of the test a perfect sphere with an aperture, forming a kind of diaphragm between pseudostome and test body	*Conicocassis pontigulasiformis*
–	Main part of the test without diaphragma	*C. platystoma*

27	Shell in lateral view flattened, pseudostome located near the center of the ventral side; length of test 160-170 μm	*C. mirabilis*
	Shell in lateral view high, at least in the fundus, pseudostome very eccentric, length of test < 120 μm	28

28	Many spines, arranged randomly; visor turned outwards	29
	One spine, long; visor not turned outwards	*C. platystoma armata*

29	Length of test 70-80 μm	*C. grelli*
	Length of test 140-200 μm	*C. adami*

30	Posterior part in lateral view strongly curved inwards, forming a perforated diaphragm, separating the visor from the fundus	31
–	Shell without a perforated diaphragm	32

31	Length of test 65-100 μm	*C. sylvatica*
–	Length of test 35-45 μm	*C. sylvatica minor*

32	Pseudostome narrow sickle-shaped, test in dorsal view ovoid = Heleopera???	*C. declivistoma*
–	Pseudostome circular or elliptical	33

33	Shell in lateral view high, height of the test is equal, slightly less or exceeds the width	34
–	Shell in lateral view more flattened, height less than width	43

34	Height of the test considerably exceeds the width and length	*C. deflandrei*
–	Height of the test approximately equal to the width of the test.	35

35	Shell with spines	36
–	Shell without spines	38

36	One spine, thick, hollow, located on the extension of the longitudinal axis of the test	*C. chardezi*
–	Spines a lot, are located throughout the fundus	37

37	Length of test 90-120 μm	*C. gibba*
–	Length of test 60-75 μm	*C. notonyx*

38	Shell length >110 μm	39
–	Shell length < 90 μm	40

39	Visor very wide, resembling the edge of a hat	*C. cordobensis*
–	Visor not so large, formed by very large grains of sand	*C. janetscheki*

40	Pseudostome subterminal, located at an angle of 45 ° to the longitudinal axis of the test	*C. sacciformis*
–	Pseudostome located on the ventral side of the test	41

41	In lateral view test in pseudostomal area almost not narrowed	*C. villiersi*
–	In lateral view test in pseudostomal area narrowed	42

42	Height of the test slightly exceeds the width	*C. gibba inermis*
–	Height of the test is slightly smaller than the width	*C. aerophila*
43	Width of test exceeds the length	44
–	The width of test does not exceed the length	45

44	Length of test 50-60 μm	*C. aculeata lata*
–	Length of test 150-205 μm	*C. compressa*

45	Pseudostome subterminal, located at an angle of 50-60 ° to the longitudinal axis of the test	46
–	Pseudostome ventrally located	47

46	Thorns 1-6, elongated test	*C. marsupiformis*
–	Spines 4-8, test wider	*C. marsupiformis obesa*

47	Shell with spines	48
–	Shell without spines	53

48	A wide flat keel is located along the perimeter of the test, the outgrowth of which forms spines	*C. horrida*
–	Keel is absent	49

49	Spines are located on both the abdomen and on the visor	*C. decloitrella*
–	Spines only on the abdomen	50

50	Shell in dorsal view trapezoidal	*C. pyriformis*
–	Shell dorsal view is oval, elliptical or ovate	51

51	There is a groove between the organic mouth area of the test and the posterior end	*C. percolahiensis*
–	Furrow absent	52

52	Pseudostome circular	*C. aculeata*
–	Pseudostome oval	C. aculeata oblonga

53	Length of test < 100 μm	54
–	Length of test > 100 μm	55

54	Shell elongate elliptical in dorsal view; pseudostome circular or semicircular, large, occupies 1/3 part of the length of the test	C. elongata
–	The test is broad-elliptical in dorsal view, pseudostome convex in the front, straightly cut from the rear; visor is lined with large xenosomes	*C. cassis*

55	Shell with internal bridges	56
–	Shell without internal bridges	57

56	Ventral surface curved, pseudostome located almost at the center	*C. kurakchayensis*
–	Ventral surface flat, pseudostome eccentrically	*C. gasparella*

57	Length of test > 200 μm, there is a wide visor in the form of the fields of a hat	*C. recurvata*
–	Shell smaller, visor not so wide	58

58	Pseudostome small, roundish, located at the bottom of a deep pre-oriental funnel	*C. invaginata*
–	Pseudostome larger	59

59	There is a groove between the organic aperture of the test and the xenosomes on the posterior end	*C. percolahiensis inermis*
–	Groove absent, posterior end usually contains large sand grains	*C. constricta*