BIOLOGY AND STRUCTURE OF HYDROPHILUS CARABOIDES 637 



turns it round and round and squeezes it. The liquid parts of 

 the food are sucked up at this time by means of a special sucking 

 apparatus of which we give a description, based on the study 

 of series of transverse and longitudinal sections of the head and 

 thorax of the larva of H . c a r a b o i d e s . 



The fore-gut of the larva described runs as a straight tube 

 from the oral aperture to its point of mergence into the stomach, 



Text-fig. 7. 



^. 



Parts of antennae of a newly-hatched {a) and a mature {h) larva at the 

 same magnification. Zeiss, ob. DD, oc. (). 



which takes place in the thorax. In this fore-gut three divisions 

 can be recognized, viz. the fore part reaching to the nervous 

 ganglia ; the middle part corresponding with the pharyngeal 

 ring of the nervous system ; and the hind or post-cerebral part, 

 or the oesophagus proper. 



The fore part is a dorso-ventrally flattened tube (Text- 

 fig. 10) with sharp lateral edges. Its upper surface is covered 

 with transverse muscular bundles (sj), which are fastened to 

 the sharp edges of the intestine. These muscles can, as I believe, 

 be regarded as sphincters of a suctorial apparatus, for when 



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