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Full text of "The Odonata of Chile"

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. 

ZOOLOGICAL SERIES 

OF 
FIELD MUSEUM OF NATURAL HISTORY 

Volume 24 CHICAGO, NOVEMBER 20, 1943 No. 32 

THE ODONATA OF CHILE 

BY JAMES G. NEEDHAM 

PROFESSOR EMERITUS, ENTOMOLOGY AND LIMNOLOGY, CORNELL UNIVERSITY 

AND 

DILLMAN S. BULLOCK 
DIRECTOR, AGRICULTURAL SCHOOL, "EL VERGEL," CHILE 

This is a preliminary report on the dragonflies of Chile in both 
their adult and their immature stages. It is based on collections 
made by the junior author mainly in the region about the Agricul- 
tural School, "El Vergel," near Angol. The immature stages were 
collected mainly from the Malleco River and from a mill canal that 
runs through the farm. Some of the adults were obtained from other 
parts of the country. 

This new material, representing all but four of the genera and 
most of the species known from Chile, enables us to present keys 
to the genera of both nymphs and adults, and descriptions and 
figures of nymphs in a number of genera in which none have hereto- 
fore been made known. Although the nymphs have not been reared, 
their adult forms are reasonably certain. 

Hitherto there has been published but one extensive paper on 
the Odonate fauna of Chile, that of Dr. Fr. Ris, published in 1904. 
His paper listed twenty-six species, and included a description and 
a figure of the nymph of one of them (Aeschna diffinis). It contained 
also the description of a new genus (Antiagrion) and a figure of the 
wing venation of one of its two species (A. gayi}. No new species 
were described from Chile in Ris's paper, and there are none in this 
one of ours. New material enables us to complete the description 
of some species of which the original describers had inadequate 
material, often only single fragmentary specimens, and to establish 
a new genus. 

No. 639 H - L 357 



358 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 24 

LIST OF THE DRAGONFLIES AND DAMSELFLIES 

OF CHILE 

ANISOPTERA 

Aeschnidae 

Phenes raptor Rambur 1842 Phyllopetalia apollo Selys 1878 

Neogomphus molestus Selys 1857 Phyllopetalia apicalis Selys 1857 

Neogomphus bidens Selys 1878 Allopetalia reticulosa Selys 1873 
Hypopetalia pestilens McLachlan 1870 Aeschna brevifrons Hagen 1861 

Petalia punctata Selys 1854 Aeschna diffinis Rambur 1842 

Phyllopetalia stictica Selys 1857 Aeschna confusa Rambur 1842 
Phyllopetalia decorata Selys 1878 

Libellulidae 

Gomphomacromia paradoxa Brauer 1864 Erythrodiplax connate Burmeister 1839 
Anticordulia villosa Rambur 1842 Orthemis ferruginea Fabricius 1775 

Erythrodiplax chloropleura Brauer 1866 Tholymis citrina Hagen 1867 

ZYGOPTERA 

Coenagrionidae 

Lestes undulatus Say 1839 Ischnura fluviatilis Selys 1876 

Antiagrion blanchardi Selys 1876 Oxyagrion rufulum Hagen 1861 

Antiagrion gayi Selys 1876 Acanthagrion interruption Selys 1876 

KEYS TO THE ODONATA OP CHILE 
Adults 

1. Body stout; wings unequal, the hind wings being broader at base. 

Anisoptera, 2 
Body slender; fore and hind wings of equal width Zygoptera, 19 

2. Eyes widely separated on the top of the head 3 

Eyes almost meeting or in contact by a point 5 

Eyes broadly in contact along their inner margins 10 

3. Face with a heavy black crossbar above the mouth; hind wing 52 mm. 

Phenes raptor 
Face all pale yellowish; hind wing 26 mm Neogomphus, 4 

4. Male with inferior appendage as long as the superior N. molestus 

Male with inferior appendage half as long as the superior N. bidens 

5. Fore wing triangle divided into 2-3 cells; six or seven brown spots along the 

fore border of the wing; hind wing 48 mm Hypopetalia pestilens 

Fore wing triangle of two cells; five spots on border 6 

6. Frons very high in front (three times the postclypeus) and divided by a deep 

longitudinal groove; hind wing 35 mm Petalia punctata 

Frons moderate, not deeply grooved Phyllopetalia, 7 

7. Larger (hind wing 48-49 mm.) ; one postcostal cell row P. stictica 

Smaller (hind wing 39-44 mm.); two postcostal cell rows 8 

8. Male with anal triangle 4-celled; frons a little notched above .P. decorata 
Male with anal triangle 3-celled; frons not notched at all 9 



-2,-t- 

// r hi /ST A / 8 
1943 ODONATA OF CHILE NEEDHAM AND BULLOCK 359 

9. Leaf -like lateral expansion on abdominal segments 7 and 8; claws black; 
hind wing 39-41 mm ........................................ p. apollo 

Leaf-like lateral expansion on segment S only; claws red; hind wing 40-42 mm. 

P. apicalis 



10. 



Hind wings with four to seven cubito-anal cross veins; stigma with brace 
vein; triangles similar in fore and hind wing ............. Aeschnidae, 11 

Hind wings with one or two cubito-anal cross veins; no brace vein to stigma; 
triangles of fore and hind wings unlike ................. Libellulidae, 14 

11. Vein Rs simple; wings streaked at base with brown; hind wing 51-58 mm. 

Allopetalia reticulosa 
Vein Rs forked; wings hyaline ...................... ' ....... Aeschna, 12 

12. Larger (hind wing 48 mm.) ................................ A. brevifrons 

Smaller (hind wing 36-37 mm.) ..................................... 18 

13. Thorax olivaceous in front, clothed with whitish hairs ........... A. diffinis 

Thorax reddish, with two yellow stripes in front ............... A. cow/wsa 

14. Fore wing with eight antenodal cross veins and no planates ............. 15 

Fore wing with ten or more antenodal cross veins and with well-developed 

planates ....................................................... 16 

15. Triangle and subtriangle without cross veins. . . Gomphomacromia paradoxa 
Triangle and subtriangle both divided by cross veins .... Anticordulia villosa 

16. Anal crossing proximal to base of vein A2 ............... Erythrodiplax, 17 

Anal crossing opposite the base of vein A2 ............................ 18 

17. Colored area of base of hind wing golden; hind wing 25 mm. . E. chloropleura 
Colored area of base of hind wing brown; hind wing 23 mm ...... E. connala 

18. Arculus in fore wing at or beyond the second antenodal cross vein; hind 

wing 40 mm ....................................... Orthemis ferruginea 

Arculus in fore wing before the second antenodal cross vein; hind wing 
35 mm ............................................. Tholymis citrina 

19. Middle fork nearer to the arculus than to the nodus; hind wing 21 mm. 

Lestes undulatus 
Middle fork nearer to the nodus than to the arculus ................... 20 

20. Front side of quadrangle longer than half the rear side; postnodal cross 

veins 14 or more ...................................... Antiagrion, 21 

Front side of quadrangle less than half the length of the rear side; postnodal 
cross veins 12 or fewer ........................................... 22 

21. Antenodal cross veins 14; hind wing 22 mm .................. A. blanchardi 

Antenodal cross veins 16-18; hind wing 26 mm .................... A. gayi 

22. Wings not stalked to anal crossing; hind wing 22 mm ..... Ischnura fluviatilis 
Wings stalked to anal crossing ...................................... 23 

23. Coloration reddish; hind wing 19 mm ................... Oxyagrion rufulum 

Coloration blackish, marked with yellow or blue; hind wing 16 mm. 

Acanthagrion interruptum 



360 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 24 

Nymphs 

1. Body stout; gills internal , Anisoptera, 2 

Body slender; gills three, caudal, leaf-like Zygoptera, 10 

2. Labium flat or nearly so 3 

Labium spoon-shaped, covering the face up to the eyes 7 

3. Antennae 4-jointed; tarsi 2-2-3-jointed; burrowers Neogomphus, 4 

Antennae 7-jointed; tarsi 3-3-3-jointed 5 

4. Lateral spines qn abdominal segments 8 and 9 only N. molestus 

Lateral spines on segments 6 or 7 to 9 N. bidens 

5. Antennae stout, slowly tapered beyond the second segment 6 

Antennae slender, bristle-like beyond the second segment Aeschna 

Unknown Allopetalia 

6. Head parallel-sided for a distance behind the eyes; lateral lobe of the labium 

broad, concave internally; abdomen with rows of conspicuous hair tufts; 
end squarely truncated Phenes raptor 

Head strongly narrowed from the eyes backward; lateral labial lobe narrow, 
taper-pointed Phyllopetalia 1 

Unknown Peialia and Hypopetalia 

7. With a pair of nipple-shaped tubercles on top of the head Anticordulia 

Without such tubercles 8 

Unknown . Gomphomacromia 

8. Abdomen with huge lateral spines, longer than the segments that bear them. 

Tholymis ciirina? 
Abdomen with very short and inconspicuous lateral spines 9 

9. Teeth on the opposed edges of the lateral labial lobes deeply incised and 

very distinct Orthemis 

These teeth obsolete Erythrodiplax 

10. Labium excessively long and slender, spoon-shaped at tip, its mentum 

narrowest in the middle Lestes 

Labium shorter, its mentum narrowest at its basal hinge 11 

11. Gills widest near the base, and regularly tapering to long and very slender 

tips Antiagrion 

Gills widest beyond the middle and abruptly tapered near the tip 12 

12. Gills cross-jointed at two-thirds their length Oxyagrion 

Gills not distinctly cross-jointed Ischnura and (l)Acanthagrion 

1 These characters are taken from Tillyard's description and figure (Biology 
of Dragonflies, p. 89) of the nymph of Austropetalia patricia from New South 
Wales, a species so like the Chilean Phyllopetalia apollo that the two were long 
considered identical. Such likeness in the adult indicates that the nymphs will 
be alike in the characters stated. 

1 Teste Fraser, who described and figured (Records Mus. Indian, 16, p. 460, 
1919) the nymph of an oriental species, Tholymis tillarga. 



1943 ODONATA OF CHILE NEEDHAM AND BULLOCK 361 

Phenes raptor Rambur 

The newly discovered nymph of this mammoth, archaic species 
is almost as remarkable as the adult that has so long been known. 
It has not been reared, but size alone will distinguish it from every- 
thing else in the fauna. Also the curious forking of the male caudal 
appendages (cerci) runs parallel in nymph and adult. The following 
description is from a single cast skin the exact collecting spot of 
which is undetermined. 

It is a sprawling hair-tufted nymph so completely incrusted 
with mud in life that some of its characters may only be seen after 
a long and difficult job of cleaning. The head is wider than long, 
with eyes set far forward, and the sides behind the eyes are parallel 
to the broadly rounded hind angles. The antennae are shorter than 
the head and very stout. Their seven segments range in length 
from base outward about as 7:4:10:6:7:6:4, and the flagellum is 
almost as stout as the second segment, with most of the taper on 
the last segment. A frontal transverse prominence below the base 
of the antennae is fringed along its margin with stout incurving 
hairs. The blackish labrum is twice as wide as long, and narrowed 
to both ends. It bears two transverse rows of similar incurving 
hairs, one marginal and the other parallel to and near the base. 

The labium (fig. 30, No. 2) is nearly flat, only a little depressed 
between its lateral lobes, not covering the face. It is very short and 
stout. Its hinge does not reach backward beyond the bases of the 
fore legs. The mentum is wider than long, parallel-sided in its 
quadrangular middle portion, strongly contracted to the hinge and 
expanded at the base of its lateral lobes. The median lobe is pro- 
duced forward, declined, bare, highly chitinized, thin, and cleft 
almost to the level of the base of the lateral lobes; the narrow cleft 
is open. The lateral lobes are short and stout, concave, rather 
squarely truncate on the ends with rounded corners. The movable 
hook is remarkably short and stout, straight to near its tip, hardly 
four times as long as its basal width. Both median and lateral 
lobes are finely and regularly denticulate on their opposed margins. 

There are fringes of short hairs on a low transverse ridge between 
the bases of the antennae and on the upper margin of each antennal 
peduncle; also on a shelf-like prominence below the front of each 
eye. The middle ocellus lies flat on the surface of the head but the 
lateral ocelli seem to lie in the outer side of a pair of mound-like 
tubercles on the vertex. Behind the frontal suture there are longi- 
tudinal lines of tufted tubercles as follows: a dorsal pair about as 



362 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 24 

far from each other as from the eyes, dwindling and converging 
caudad; also two lateral more continuous rows at the sides, more 
uniformly tufted. 

The disk of the prothorax is small, about half as long as wide, 
and bears a short row of low tubercles on its projecting lateral 
margins. Below these there are tufted tubercles projecting above 
the front coxae. Above the base of each middle and hind leg there 
is a shelf-like, hair-fringed prominence, and farther caudad on the 
side there is a strong erect tubercle. 

The legs are rough and indistinctly scarred, with tarsi 3-3-3- 
jointed. The hair on the legs appears mostly in tufts on the femora 
and in lines on the tibiae (see fig. 29) . All tibiae terminate in four 



FIG. 28. Diagrams illustrating the terminology of Odonate wing venation. 

NUMBER 

1. Diagram of the principal veins and their connections. 

2. The wings of Cordulegaster sayi. 

3. Diagram of Gomphine wing base. 

4. Diagram of a Libelluline wing base. 

5. Diagram of an arculus and its sectors (Mi- 3 and M<). 

6. The fore wing of Cyanocharis valga. 

1. Part of wing base of Caliphaea consimilis. 

8. The fore wing of Telebasis salva. 

9. Part of wing base of Telebasis salva. 

10. Stigma of Anomalagrion hastatum. Female with brace vein x. 



ABBREVIATIONS 

A. anal vein mr. 

Ac. anal crossing 

Al. or al. anal loop n. 

an. antenodal cross veins o. 

a. pi. apical planate P- 

or. arculus <7- 

&. basal subcostal cross vein R- 

br. bridge Rs. 

Bs. mid-basal space; space f- pi- 

before the arculus s. 

Brs. basal radial space Sc. 

C. costa set. 

Cu. cubitus sn. 

g. gaff (fused portion of veins sq. 

Cu 2 and Ai) si. 

h. hyper triangular space t. 

M. media tr. pi. 

m. membranule . 

Ma. medio-anal link 

Mf. middle fork x. 

m. pi. median planate 



midrib (bisector of anal 

loop) 
nodus 

oblique vein 
patella 
quadrangle 
radius 

radial sector 
radial planate 
subtriangle 
subcosta 

sectors of arculus 
subnodus 
subquadrangle 
stigma 
triangle 

trigonal planate 
point at which petiolation 

(stalk) of wing base ceases 
brace vein to the stigma 




FIG. 28. Diagrams illustrating the terminology of Odonate wing 
venation. See explanation on opposite page. 



363 



364 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 24 

stout spines at the base of the tarsi, two on each side. Each of the 
two basal tarsal segments bears beneath a double row of smaller 
spines (fig. 30, No. 1) growing larger distally, and the third joint bears 
a pair of strong smooth claws. The wing cases reach backward to 
the fifth abdominal segment. 

The abdomen is moderately depressed and widest on segment 6. 
There are no dorsal hooks at all; instead there is a mid-dorsal low 
streak that lies between two submedian lines of double, large, con- 
spicuous hair tufts, the outermost row on tubercles. There are no 
lateral spines; instead, the sides of the segments are broadly rounded 
with a slight notch in the midst of their tufted margins toward the 
rear. There are two additional lines of hair tufts on each side of the 
abdomen; one midlateral on the apical carinae, larger; and a minute 
tuft of a few hairs farther out and toward the antero-lateral angle 
of each segment. The mid-dorsal length of abdominal segments 6 
to 10 is about as 10:9:9:8. The caudal appendages have a remark- 
able development in this male specimen, corresponding to those 
of the adult insect. The forked laterals are blunt-tipped and have 
something of the downy appearance of budding staghorns in the 
velvet. The superior is already decurved between the laterals and 
greatly elongated. The inferiors are shorter, invisible when viewed 
from above, triquetral and sharp-pointed, but densely clothed with 
tawny hair externally and covered at the base by a yellow hair 
fringe that springs from the apical margin of segment 10. 

Length 48 mm.; abdomen 30; hind femur 10. Width of head 10; 
of abdomen 13. 

Hypopetalia pestilens McLachlan 

Of this very beautiful endemic species we have not yet obtained 
the nymph, but we wish to record a fine male adult from high up in 
the Andes, only a few miles from the Argentine border. It is rare 
about Angol, but occurs in one region near Cholchol, where it is 
common in September. It appears to be an early spring species, 
not being seen after the end of the year. It has been observed in 
flight over stagnant ponds. 

Seven purplish spots along the costal border of each wing will 
readily distinguish it from all other Odonata. Dr. Erich Schmidt 
has recorded (7th Internat. Congress, 3, p. 1501, pi. 163, figs. 1-3) 
the pattern of its wings as having been used in the design of a cloth 
for women's dresses, and has published an excellent photograph of 
a pair of wings and a dress of this design on display. 




FIG. 29. Nymph of Phenes raptor. 



365 



366 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 24 

Neogomphus Leach 

The drying up of a mill run on the farm at "El Vergel" made it 
possible to collect from the exposed stream bed a large number of 
nymphs of this peculiar endemic genus. They are very similar to 
the nymphs of Octogomphus from California. Two species were 
present and they correspond to the two species of adults that have 
been taken in the same locality and may be referred to them by 
name with hardly any doubt. 

Neogomphus molestus Selys 

This was the commoner of the two species. This is a concolorous 
nymph, grayish brown and somewhat covered with silt. The head 
is wedge-shaped, widest at the level of the hind margin of the eye. 
The third joint of the antennae is about twice as long as the two 
basal joints taken together, dilated to an oval form and fringed at 
the edges with long soft hair. The button-like fourth joint is very 
rudimentary and occupies a notch in the middle of the terminal 
margin of the third. The mentum of the labium is a third longer 
than wide and rather regularly narrowed from outer end to basal 
hinge, with a very slight basal narrowing. The median lobe of the 
labium (fig. 30, No. 5) is convex and in the middle of its front margin 
bears three minute brown denticles and a bordering fringe of hairs. 
The lateral labial lobe is scarcely hooked at the tip where its outer 
margin beyond the movable hook is regularly incurved to end at a 
terminal denticle on the inner margin. There are about nine denti- 
cles on that margin, each truncated so as to point caudad, and they 
diminish in size proximally and end at its basal third. 

The prothorax is about as wide as the head, with its roundish 
dorsal disk about a third narrower. The fore and middle tibiae bear 
strong end hooks. All femora bear the usual longitudinal scars, 
and all the legs are fringed with hairs. 

The fore wings lie parallel upon the back, and the hind wings 
above them lie with their tips a little convergent. 

The abdomen is widest on segment 5, beyond which level it is 
slowly and regularly tapered to the tip. There are no dorsal hooks 
at all, but there are some mid-dorsal hair tufts on the basal segments, 
also some scattered hairs below the wing pads at the sides. There 
are short triangular lateral spines on segments 8 and 9. The mid- 
dorsal length of the last three abdominal segments is about as 
10:10:6. The bluntly tipped caudal appendages are twice the mid- 



1943 ODONATA OF CHILE NEEDHAM AND BULLOCK 367 

dorsal length of the tenth segment, the superior one almost the length 
of the inferiors, the laterals less than half as long. 

Length 24 mm.; abdomen 15; hind femur 4.5. Width of head 5; 
abdomen 6. 

Neogomphus bidens Selys (fig. 30, No. 7) 

This species occurred in the bed of the mill run more sparingly 
than the preceding, perhaps in the proportion of one to ten. It is 
so similar to N. molestus that there is no need to do more than 
point out the differences by which it may be distinguished. 

It is a little larger (length 28 mm.) ; lateral spines occur regularly 
on segments 7 to 9 of the abdomen and sometimes also on segment 6; 
and the inner margin of the lateral lobe of the labium (fig. 30, No. 6) 
is a little more concave, is armed with fewer and somewhat larger 
teeth, and the terminal tooth or end hook projects a little more 
prominently inward beyond the general level of the other teeth. 

Anticordulia gen. nov. 

Type Cordulia villosa Rambur 

We have nymphs and adults of this species, taken together near 
"El Vergel" and doubtless belonging together for there is no other 
regional Corduline to which they may by any possibility be referred. 
The nymphs show clearly that the species does not belong in the 
genus Somatochlora as has long been supposed. They show much 
greater resemblance to nymphs of Neurocordulia and Epitheca but 
are quite distinct from either of these. 

The triangle and subtriangle of the fore wing of the adult are as 
in Somatochlora, two- and three-celled respectively, and in the hind 
wing the triangle is generally two-celled; in only one (female) speci- 
men have we seen a second cubito-anal cross vein. The space 
beyond the triangle in the fore wing is scarcely narrowed to the wing 
margin, veins M 4 and Cu, being approximately parallel all the way 
out. Vein M 2 is slightly undulated in the fore wing. There are but 
five antenodal cross veins in the hind wing. In the anal area of the 
hind wing there are three rows of cells paralleling the weakly devel- 
oped vein A 2 , which is the hind border of the anal loop, and the cells 
of these rows are not strikingly differentiated in size as in Somato- 
chlora (where with but two rows present, the cells of the inner row 
are three or four times as large as those in the marginal row). The 
base of vein A 3 is less closely approximated to the anal crossing than 



368 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 24 

in Somatochlora, and the cells within the anal loop are less enlarged 
toward the ends of it. 

It disagrees with Paracordulia Martin in type of male genitalia, 
in lack of convergence of veins M 4 and Cu, at the wing margin, in 
having but five antenodal cross veins in the hind wing, and in having 
three cell rows in the anal area behind the anal loop; in these 
characters Paracordulia is more like Somatochlora. 

Martin has figured the caudal appendages of the male for Anti- 
cordulia villosa (1906, p. 20, fig. 15). The subgenital plate of the 
female has not been described or illustrated. It is elongate triangu- 
lar, three-fifths as long as the ninth sternum, against which it lies 
flat. It is divided for two-thirds of its length by an open parallel- 
sided narrow slit, and the tips on either side of the slit are rounded. 

The nymph (fig. 30, No. 8) is rather smooth, with broadly de- 
pressed, oval, almost circular abdomen. Head widest across the 
laterally prominent eyes, with low hind angles and concave occiput. 
Antennae with the length of the seven joints as 8:9:10:7:8:10:9. 
Between the antennae is a low transverse prominence thickly beset 
with microscopic prickles. The top of the head bears two prominent 
nipple-shaped tubercles. 

Disk of the prothorax much wider than long, bordered on its 
convex rear margin with a rim that runs out laterally into an obtuse 
prominence. Legs long, thin and bare except for a few scattering 
hairs. Labium short and broad, its hinge just reaching the meta- 
sternum. Lateral setae seven on each side; mentals ten or eleven, 
the sixth longest. Lateral lobes broadly triangular, their 
opposed margins armed with about seven deeply cut and serrately 



FIG. 30. Nymphs 

1. Phenes raptor, hind tarsus and tip of tibia. 

2. Phenes raptor, labium (ML, median lobe; LL, lateral lobe; H, movable hook). 

3. Oxyagrion rufulum, tip of lateral labial lobe. 

4. Acanthagrion interruption, tip of lateral labial lobe. 

5. Neogomphus molestus, median and lateral labial lobes. 

6. Neogomphus bidens, lateral labial lobe (EH, end hook; MH, movable hook). 

7. Neogomphus bidens, dorsal view of nymph. 

8. Anticordulia villosa (DH, dorsal hook; LS, lateral spine). 

9. Anticordulia villosa, tip of lateral labial lobe, showing teeth. 

10. Antiagrion sp., antenna. 

11. Antiagrion sp., tip of lateral labial lobe (EH, end hook; MH, movable hook). 

12. Antiagrion sp., mentum and lateral lobe of labium showing raptorial setae. 

13. Antiagrion sp., head. 

14. Antiagrion sp., end of abdomen showing gills and ovipositor. 




56 14 

FIG. 30. Nymphs. See explanation on opposite page. 



369 



370 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 24 

arranged teeth (fig. 30, No. 9), the teeth armed with spinules number- 
ing from one on the foremost tooth to about seven on the hindmost. 
The movable hook is slender, straight to near the tip, and then 
slightly incurved. 

Abdomen much depressed, broadest on segment 7, narrowing 
rapidly forward and still more rapidly backward, concolorous except 
for two longitudinal midlateral rows of round brown spots on a paler 
ground. Lateral spines on segments 4 to 9 regularly increasing in 
length and strength caudad, on 9 distinctly incurved. They are 
arranged about the curving abdominal margin like the teeth of a 
circular saw. All are sharply pointed and those of 9 are spaced more 
than their own length apart from the apex of 10. Segment 10 is 
annular and inserted into the apex of 9. Dorsal hooks on 4 to 9; 
on 4 a minute rudiment; on 5, larger, blunt-tipped, and erect; and 
on 6 to 9, higher and laterally flattened but with eroded tips, increas- 
ingly declined caudad; on 7 and 8, largest. The mid-dorsal length 
of the last four segments is as 10:9:8:3, with the appendages on the 
same scale as 7. Appendages stout, subtriangular, sharp-pointed, 
superior and inferior of about equal length, the laterals a little 
shorter. On the under side of the apical margin of 9 there is a thin 
fringe of long hairs. 

Length 25 mm.; abdomen 15; hind femur 9. Width of head 8; of 
abdomen 12. 

Antiagrion sp. 

The nymph of this peculiar endemic damselfly is rather stout, 
long-legged, with flat head (fig. 30, No. 13), banded legs, short thick 
abdomen and very long, slenderly tapering gills. The eyes are large 
and very prominent. Behind them the head tapers to the bulging 
hind angles, between which is a deep occipital excavation. Around 
the hind angles the skin is beset with minute retrorse prickles. The 
seven-jointed antennae (fig. 30, No. 10) are pale, ringed with brown 
subapically on the middle segments. The length of the segments is 
about as 6:8:10:8:7:6:5. The labium (fig. 30, No. 12) is armed with 
five lateral and two mental setae each side, with six or more stout 
spinules on the lateral margin of the mentum. The middle lobe is 
prominent; its margin is beset with regularly spaced microscopic 
spinules. The terminal border of the lateral lobe (fig. 30, No. 11) 
between movable and end hooks is inclined toward the latter and 
armed with a row of microscopic denticles the innermost one of 
which is of larger size. 



1943 ODONATA OF CHILE NEEDHAM AND BULLOCK 371 

The prothorax is flattened above and slopes upward behind to a 
curving, marginal, elevated rim. The legs are rather long, pale in 
color, ringed twice with brown toward the outer end of the femora, 
and twice more, less distinctly, on the tarsi. 

The abdomen is brownish above with a pale mid-dorsal line and 
a wider pale band on each lateral margin. There are neither dorsal 
hooks nor lateral spines. The ovipositor (fig. 30, No. 14) of a single 
well-grown female specimen, perhaps contracted somewhat, extends 
beyond the abdomen for more than the length of segments 9 and 10. 
The gills are very long and narrow and taper from a thick base 
regularly outward to excessively slender tips. Their margins are 
thickly fringed with hairs. The lateral gills are triquetral at base 
by reason of a stout midlateral keel that also tapers outward almost 
to infinity. 

One well-grown female specimen (perhaps in the penultimate 
instar), and another much smaller. The wings of the former are 
not well enough preserved to show the complete venation, but they 
show two items of it that justify the reference of the nymph to 
Antiagrion. The quadrangles are longer on the front side, and the 
postnodal cross veins are more numerous (sixteen) than in related 
local genera. 

Length of body 9 mm.; gills 6 additional; abdomen 6; hind femur 
3.5. Width of head 3; of abdomen 2. 

Oxyagrion rufulum Hagen 

This is a pale slender nymph with brown-ringed legs and a pair 
of brownish submedian dorsal stripes along the abdomen. The 
skin is beset with minute brownish prickles on all the broader sur- 
faces of the body and head. The head is flattened above, with large 
and very prominent eyes, behind which it is narrowed to very 
prominent broadly rounded hind angles, where the prickles of the 
skin are larger. The occipital excavation of the rear of the head is 
wide. The relative length of the seven antennal segments is as 
6:7:10:7:6:5:4. The labium is armed with four or five lateral 
setae and with three or four (usually three) mentals, and the end 
of the lateral lobe is as shown (fig. 30, No. 3). 

The legs are ringed more or less distinctly with brownish color, 
two rings on each femur and one on each tarsus. The wing cases 
extend backward to the middle of the sixth abdominal segment. 
The gills are cross-jointed at two-thirds their length and widest at 



372 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. 24 

the joint, with the lower margin of the lateral ones spinulose-serrate 
out to the joint. Their tracheation is very twig-like. 

Length of body 15 mm.; gills 8 additional; abdomen 10; hind 
femur 4. Width of head 4; of abdomen 3. 

This species was first described by Hagen (1861) from an incom- 
plete male specimen from northern California; more fully by Selys 
(1876) with females from Chile added; and still more fully by Calvert 
(1909), with drawings of the male appendages added. It has not 
been found again in California. Was Hagen's specimen a stray 
carried by air currents, or was the locality on the label erroneous? 

Acanthagrion intermptum Selys 

. This nymph is so similar to that of the preceding species that 
there is no need to do more than point out the differences distin- 
guishing them. Nymphs of the two species came together accom- 
panied by adults of two corresponding species from the same locality. 
No other nearly related or closely similar Agrionines accompanied 
these. Neither was reared. The clues to their identity were found 
in size and in wing venation. 

This Acanthagrion nymph is smaller, measuring in length of body 
13 mm., with the gills 7 mm. additional. The relative length of the 
seven segments of the antennae (in the single specimen in which they 
were preserved) is as 5:7:10:7:6:5:4. The raptorial setae on the 
labium are six laterals and four mentals (in three specimens). The 
vestigial transverse joint in the gills is about midway of their length. 
The tracheal twigs are more openly branched. 

The developing wings were not in condition to show the critical 
venational character distinguishing these two species. It is found 
in the fore wing where the wing base is not stalked out to the anal 
crossing as it is in Oxyagrion. As I was able to see that character 
in the nymphs here referred to Oxyagrion, this nymph would seem to 
be safely determined by exclusion as belonging to the one other 
species that was commonly collected. 

The adult of this species was fully described by Selys (1876) and 
again described and illustrated by Ris (1913). 

It is not certain that this species properly belongs in Acantha- 
grion. We find no character in its nymph that will distinguish it 
from the nymph of Ischnura. The adult male is also like Ischnura 
in that the mid-dorsal apical margin of the tenth abdominal segment 



1943 ODONATA OF CHILE NEEDHAM AND BULLOCK 373 

is prolonged and rather deeply divided into a pair of submedian 
prominences. We leave it where it is, pending the discovery of the 
nymph of the typical Acanthagrion. 



REFERENCES 

CALVERT, P. P. 

1909. Contributions to a Knowledge of the Odonata of the Neotropical Region, 
Exclusive of Mexico and Central America. Ann. Carnegie Mus., 6, p. 183, 
pi. 3, figs. 49, 50, male app. Oxyagrion rufulum. 

HAGEN, HERMANN 

1861. Synopsis of the Neuroptera of North America, with a List of the South 
American Species. Smithson. Misc. Coll., 4, xx + 347 pp. 

MARTIN, RENE 

1906. Cordulines. Collections Zoologiques du Baron Edm. de Selys Long- 
champs. Catalogue, syste'matique et descriptif, 17, 98 pp., 3 pis. (col.), 
99 figs. 

Ris, FR. 

1904. Odonaten. Ergebnesse der Hamburger Magalhaensischen Sammelreise, 

Hamburger-Naturhist. Mus., pt. 7, No. 3, 44 pp., pi. and text figs. 
1913. Neuer Beitrage zur Kenntnis der Odonatenfauna von Argentina. Mem. 

Soc. Ent. Belg., 22, p. 66, figs, of male app. of Acanthagrion interruptum. 
Reports A. interruptum from Penco (Reed Coll.) and Concepcion (P. Herbst). 

SELYS-LONGCHAMPS, E. DE 

1876. Synopsis des Agrionines, 5me Legion. Bull. Acad. Roy. Sci. Belg., (2), 
41, pp. 247-322, 496-539, 1233-1309. 



UNIVERSITY OF ILLINOIS-URBAN*