Invertebrate Gallery of the Indian Museum. 49 



groups which have been classed together by Professor Ray 

 Lankester as a distinct phylum under the name of Pod- 

 ax onia. 



The reasons why these three groups have been placed 

 together near to the Annelida group cannot be discussed 

 here, where it is enough to say that they follow from the 

 fact that the larval forms of all four groups have many 

 characters in common. 



I. GEPHYREA. 



[®e0tern giJitU-fa0e 44]. 



The Gephyrea, or Spoon-worms, are entirely marine. 

 They differ from the Chxtopoda in not having the body 

 segmented and in not having parapodia and setse. 

 Sipunculus, of which several specimens are exhibited in 

 Case 44, illustrates this class. 



In Sipunculus we see a papillated proboscis, at the end 

 of which is the mouth-opening. The rest of the body is 

 marked by deep longitudinal and transverse furrows, the 

 latter dividing the body into a series of rings which, how- 

 ever, are only superficial and must not be confounded with 

 the segments of Annelids. 



In the Indian Seas Sipunculus has been found on the 

 Andaman reefs and in the depths of the Andaman and 

 the Laccadive Seas. 



The details of the internal anatomy of Sipunculus can 

 be seen in the dissected specimen, which has been laid 

 open along the ventral surface, a little to the right of the 

 middle line of the body. The dissection is accompanied 

 by an explanatory drawing. 



2. BRACHIOPODA. 



[SEestan eUaU-nis^s 44-45]. 

 The body of the Brachiopoda is enclosed in a bivalve 

 shell, something like the shell of a Mussel or of a Cockle in 

 external appearance, and so far as mere outward resem- 

 blance goes the adult Brachiopoda have little likeness to 



D 



