THE 



BRITISH NATURALIST. 



NEW SERIES, 



SOME CURIOUS AQUATIC LARVAE. 



BY GEORGE SWAINSON, F.L.S. 



( Continued from page 256.) 



Since the preceding notes were in the printer's hands, my friend Dr. 

 Bousfield, of London, has cut for me serial sections of Dixa longi- 

 tudinally, which have satisfied me that the rotatory tufts, ordinarily 

 speaking, are on the top of the head ; but the habits of the larva are so 

 abnormal that the mouth opens, and the tusks are inclined, and the 

 eyes are placed as if the tufts were in the lower jaw. If the head were 

 placed as in ordinary larvae, the long bristles on the underside of the 

 first segment of the body would not only interfere with the rotatory 

 action of the tufts, but would hinder food entering the mouth. Their 

 action really is, as Meinert says, to keep the head clear of the side of 



EXPLANATION OF PLATE XII. 



Fig. i. & 2. — Transverse sections of Dixa Larva — 



a. Pseudopods, showing in Fig. i. hooklets. 



b. Intestinal canal with undigested food. 



c. Trachea much branched running on either side of intestine. 



d. Ventral nerve cord under intestine. 



e. Museles of false feet. 



/. Dorsal skin showing minute hairs. 

 Fig. 3. — Marine form of Trichoptera in transparent capsule. — (Nov Spec, G.S.) 

 Fig. 4. — Oxyethha larva from Loch Tay. 

 Fig. g. — Claw of marine larva. 

 Fig. 6.— Do. Loch Tay larva. 

 Fig. 7. — Head and jaw of marine larva. 

 Fig. 8.— Do. Loch Tay larva. 



