RADIATA. 649 



a balancer, in most species ; mouth composed of a sucker, consisting of a 

 variable number of scaly setaceous pieces, either inclosed in the upper fur- 

 row of a sheath, or inarticulated proboscis, and terminated by two lips, or 

 cased in one or two plates. 



Culex pipiens.— The Gnat. Plate Ixxi. fig. 4. Described, vol. iv. page 395. 



Tipula oUeracea.— The Common Tipula. Plate Ixxi. fig. 1. Described, 

 vol. iv. page 394. 



Tabanus tropicus. — The Tropical Tabanus. Plate Ixxi. fig. 7. Mouth 

 with a membranaceous proboscis; two equal lips; haustellum projecting 

 and received into a groove ; antennae short, approximate and cylindrical 

 with seven articulations ; of a dull brown and yellow colour. Inhabits Bri- 

 tain. 



Stratiomps chamceleon. — The Chameleon Fly. Plate Ixxi. fig. 8. Head 

 yellow, with brown eyes, and black antennse, thorax brown, covered with 

 yellow fawn coloured down ; abdomen blackish or dusky above, with three 

 spots of yellow on each side, and one at the tail. Inhabits Europe on 

 flowers. 



Conops macroceplutla. — The Lean-Headed Conops. Plate Ixxi. fig. 10. 

 Mouth witli a porretted, geniculated, rostrum ; antennae clavated ; the 

 clava acuminated, luhaoits Europe. 



(Estrus bovis. — The Ox Gad-Fly. Plate Ixxi. fig. 6. Deseribed, vol. iv. 

 p. 400. 



Hippobosca equina. — The Horse Hippobosca, or Horse Gad-Fly. Plate 

 Ixxi. fig. 3. Described, vol. iv. p. 400. 



DIVISION IV._RADIATA. 



This division is divided into six classes. 



CLASS X.— ECHINODERMATA. 



With a suborbicular body, having a crustaceous covering, radiated, de. 

 viiid of a head, eyes, and articulated feet ; mouth placed below, simple, or 

 multiform; having compound digestive organs; with exterior tubes or 

 pores for respiration. 



Echinus esculentus. — The Edible Sea Urchin. Plate Ixxxiv. fig. 7. De- 

 scribed, vol. iv. p. 80. 



Spatangus purpureus. — The Purple Spatangus. Plate Ixxxiv. fig. 0. 

 Heart-shaped, with four lanceolate compartments, which are placed, with 

 the larger tubercles, in a zigzag form. Inhabits the European seas. 



Asterias rubens. — The Red Star-Fish. Plate Ixxxiv. fig. 9. With five 

 lanceolate, papillous, and spinous rays ; papillae of the back scattered, and 

 set nearly in rows. Inhabits the European seas. 



CLASS XL— TUNICATA. 



Gelatinous or coriaceous biferous animals; with double coats, isolated 

 placed in groups, or adhering together in a common mass. 



3i3 



