134 



MR. J. M. BROWN ON THE ANATOMY OF 



The blood consists of a colourless fluid containing numerous large corpuscles (PL 25. 

 lig. 17), generally somewhat spherical or ovoid, but sometimes more spindle-shaped, 

 and containing a large nucleus. Occasionally tbey are binucleate, this probably, however, 

 being seen in those in process of division. 



Zoological Laboratory, 

 University of Sheffield. 



EXPLANATION OP PLATES 24^27. 



Contractions used 



Note. — Figs. 1-20 refer to T. maxima. 



Figs. 21 & 22 refer to an undetermined aquatic species, which is very like T. eluta. 



Fig. 1. Larva of T. maxima, from a preserved specimen. 



2, 3, & 4. Posterior end of the same, in side view, ventral view, and posterior view respectively. 

 5 & 5 a. Dorsal triangular lobe, with marginal fringe and sensory hairs. 



6. Longitudinal vertical section through a spiracle. (Slightly diagrammatic.) 



7. Radial section across the spiracle cover. 



8. Tangential section across the same. • 



9. Diagram showing the arrangement of the parts forming the spiracle cover. 



10. Portion of a transverse section across the stigmatic chamber. 



11. Some of the chitinous hairs more highly magnilied. 



12. Transverse sections across a bundle of air-tubules, a, near the origin : b, more distal. 



