220 



MANUAL OF THE MOLLUSCA. 



? Ismenia (pectunculus) King. Coral rag, Europe. Valves ornamented 

 with corresponding ribs ; loop trebly attached. 



? Waltonia (Valenciennei) Dav. New Zealand. Perhaps the fry of Ter . 

 rubicunda, with the reflected part of the loop wanting. 



Fig. 124. Argiope decollata. 



Fig. 125. A. Neapolitan^ Sc. 



ARGIOPE, Eudes Deslongchamps. 



Etym. Argiope, a nymph. Syn. Megathyris, D'Orb. 



Type, A. decollata, PI. XV. %. 10. Fig. 124126. 



Shell minute, transversely oblong or semi-ovate, smooth or with corre- 

 sponding ribs; hinge line wide and straight, with a narrow area to each 

 valve ; foramen large, deltidium rudimentary ; interior of dorsal valve with 

 one or more prominent, sub-marginal septa ; loop two or four-lobed, adhering 

 to the septa, and more or less confluent with the valve. 



Fig. 126. A. decollata, ^p ; dorsal valve with the animal, from a specimen dredged by 

 Prof. Forbes in the ./Egean. The oral aperture is seen in the centre of the disk. 



Animal with oral arms folded into two or four lobes, united by mem- 

 brane, forming a brachial disk fringed with long cirri : mantle extending to 

 the margins of the valves, closely adherent. 



Distr, 4 sp. N. Brit. Madeira, Canaries, Medit. 40 105 fathoms. 



Fossil. 5 sp. U. Greensand . Europe. 



Interiors of dorsal valves magnified, from the originals in Coll. Davidson. 



