THE PENTASTOMIDA. 



The Pentaatomida are elongated vermiform animals, the 

 bodies of which are divided by close-set transverse coustric- 



Fie* 93.Pentastomum tcenioides.A.. Male. B. Female. C. Anterior end of the body : 

 <l, anterior hooks ; >, posterior hooks ; d, mouth ; c, rudimentary palpiform cr- 

 gane. (After Leuckart.) 



tions into numerous short segments. At first sight they 

 appear to be entirely devoid of appendages, but, on careful 

 inspection, four curved hooks are found, two on each side of 

 the mouth, which is situated rather behind the anterior ex- 

 tremity of the body. Each hook is solid, and its base pro- 



PIQ. 94. Embryo of Pentastomum tantoldes. 



jects into the cavity of the body and gives attachment to the 

 muscular bands by which it is moved. 



The mouth is surrounded by a chitinous ring ; a narrow 



