1909. | ON GROWTH-STAGES IN BRITISH SPECIES OF CORALS. 285 
EXPLANATION OF THE PLATES. 
PratEe XXXII. 
Development of Agrionid Dragonflies. 
Fig. 1. The egg of Ischnwra elegans Lind., some hours before hatching. 
Fig. 2. Part of the same egg, at a later stage, showing the shell-rupture and the 
vesicle formed, and the head just commencing to move forward. 
Fig. 3. Part of the egg, at a still later stage, showing the head X almost filling the 
vesicle. a is the point at which the membrane will rupture for the escape 
of the pronymph. 
Fig. 4. The pronymph immediately after its escape from the ege. 
5. Prothorax, dorsal view, of the imago of Agrion puella L., 9. 
Fig. 6. Prothorax, dorsal view, of the imago of Agrion pulchellum Lind., °. 
Prate XXXIV. 
Development of Agrionid Dragonflies. 
Figs. 1, 2, 3 show the last stages of wing-development in the nymph of Ischnura 
elegans Iand., in this case stages 10, 11, and 12. The drawings are from 
the moulted skin. 
Fig. 4. The “mask” of Agrion pulchellwm Lind., in the first stage, upper side. 
Fig. 5. One of the labial palpi of the same “mask” X about 400. 
Fic. 6. The “ mask” in the third stage. 
Fig. 7. The “mask” in the seventh stage, showing the palpi almost closed down on 
the anterior border of the labium. The stiff hairs are so situated that when 
the nymph is feeding they assist in holding the food, the mouth being 
situated jurt bove b. 
4. Growth-Stages in the British Species of the Coral Genus 
Parasmilia. By W. D. Lane, M.A., F.Z.S8., British 
Museum (Nat. Hist.). 
[ Received February 16, 1909. | 
(Text-figs. 38-46.) 
I. Carruruers’ “ PHASES’ IN CARBONIFEROUS CoRALS. 
In the early numbers of last year’s ‘ Geological Magazine’ an 
article by R. G. Carruthers appeared on some simple Carboni- 
ferous Corals*. In it stress is laid on the necessity of cutting 
serial sections of corals and for the determination of species 
according to their growth-stages. It is shown that Carboniferous 
corals previously described as various species of Zaphrentis are 
really different forms of Caninia cornucopie Michelin, and that 
during development five “ phases” can be recognised, occurring in 
the following order: (1) that corresponding with Zaphrentis ver- 
micularis de Koninck; (2) with Lophophyllum dumonti Edwards 
& Haime; (3) with Zaphrentis nystiania de Koninck; (4) with 
Zaphrentis edwardsiana de Koninck ; (5) with Caninia cornu-bovis 
Michelin. 
It is important that the term ‘“ phase” is used to designate 
these forms and not the implicatory “ stage,’ and the reason is | 
* R. G. Carruthers, 1908, Geol. Mag. pp. 20, 63, & 158. 
