ORGANS OF DIGESTION. 



those of the articulated classes which we observe in the ex- 

 ternal form of their body, and in all their organs of relation. 

 The mouth, as seen in the pentalasmis (Fig. 11 7. D. E. F. 

 a. a. 0.), provided with serrated mandibles which move 

 transversely, and with a pair of maxillae with rudimentary 

 palpi attached to them, opens by a short contracted oeso- 

 phagus (117- E. b.} with longitudinal internal folds, into 

 a capacious sacculated stomach (11 7- E. c.) furnished with 

 t\vo large ccecal appendices and closely surrounded by the 

 numerous small lobes of the liver (117- F. c.) Two distinct 

 lobulated salivary glands (1 17- D. h. F. b.) pour their secre- 

 tion into the mouth, and the numerous small compacted 

 lobes of the liver (117- D. e. F. c.) open freely by short ducts 

 with wide orifices (117- E. d. d.) into the cavity of the 

 stomach, as in most invertebrated classes. From the con- 

 tracted pyloric orifice of the stomach, the wide and corrugated 

 intestine (117- D- b. c. E. e. F. d. d.) passes along the dorsal 

 convex part of the body, presenting an annulated appearance, 

 and having a distinct muscular coat of transverse fibres and 

 longitudinal bands, but without convolutions or a distinct 

 mesentery. The concavity left on the fore part of the 

 body, by this wide curved intestine, which follows the course 

 of the closed posterior portion of the shell (Fig. 13. i. e.), 

 is occupied chiefly with the mass of the ovary (Il7 D. k.) 

 and the wide oviduct (117- D- 2.) surrounded with the 

 testicle. The rectal portion of the intestine (117. D- c. F. d.) 

 opens, along with the oviduct, into the base of the long 

 capilkited muscular tubular proboscis (117- D- c. d.), by 

 which the residue of digestion is conveyed freely from the 

 interior of the shell to which the animal is fixed. The food 

 is brought within the cavity of the mantle, and within the 

 reach of the three pairs of maxillae, by means of the respi- 

 ratory currents and by the incessant movements of the long 

 curled ciliated feet, and it appears to be recognized by the 

 palpi, the upper and lower lip, and rudimentary antenna, 

 without the aid of organs of vision which are here oblite- 

 rated in the fixed adult animals, as they are in the fixed 

 adult state of the epizoa. By the lobulated or conglomerate 

 form, and the great development of the biliary and salivary 

 glands, and by the numerous wide ducts by which the liver 

 communicates with the cavity of the stomach, the cirrhopods 



