420 Dr. E. S. Morse on the Early Stogps 



seen in this figure. Two lateral bands are seen holding the 

 stomach in position ; and these appear to be attached to the 

 crura, though they probably pass by them and become at- 

 tached to tlie haemal valve. These are the lateral gastro- 

 parietal bands, first described by Ifuxlej'. 



The walls of the blind intestine are yet light brownish in 

 colour, as in the Phylactolsemata, and, as before remarked, 

 are hepatic. A kidney-shaped area is faintly defined on the 

 Tieural valve. A portion of this outline indicates the point of 

 attachment of the perivisceral wall. 



In fig. 14 a an enlarged view of the digestive sac and adja- 

 cent parts of fig. 14 is shown. The liver in this stage com- 

 municates with the stomach by large openings on each side ; 

 and fine granules were seen rapidly circulating to and fro 

 from the liver to the stomach. The faeces, rolled into a spiral 

 and pyrifonn shape, were constantly in motion by the action 

 of the cilia lining the stomach. This mass was frequently 

 urged toward the mouth before it was finally discharged. 

 The passage of the fsBces through the moutli was repeatedly 

 witnessed, though, after the careful investigations of Huxley, 

 Hancock, Lacaze-Duthiers, and Gratiolet, no further proof is 

 needed of the absence of an anal outlet to the intestine of this 

 and allied species. 



The experiments of Mr, Hancock, such as bursting the in- 

 testines under a compressor, were performed on many living 

 adult specimens, yet in no case was the slightest evidence of 

 an anal outlet observed. 



Fig. 15 represents a stage but slightly advanced from fig. 

 14. The cirri are more numerous, but still spring from a cir- 

 cular lopho])hore. 



Fig. 17, PI. XVI., represents a considerably advanced stage, 

 in Avhich the lopliophore, before circular, has rapidly assumed 

 its hippocre]ndan character — ra])idly, since forms nearly of the 

 same size show no marked indications of change ; for in one 

 example we may have a circular lophophore, or one showing 

 but slight indentation, while in another example, hardly dif- 

 fering in size, we have the lateral processes well advanced in 

 development. It is possil)le that we may have here a featiire 

 observed by Fritz Miiller in the young Disrina described by 

 him : he mentions the remarkable fact of having repeatedly 

 captured free-swimming young which had evidently advanced 

 further in their develo]unent than the oldest of those which 

 had already fixed themselves. It will be noticed that in this 

 stage (fig. 17) the cirri stand erect upon the arms tthat is, 

 ])ointin,L!: towards the anterior nuirgin i>f tiie shell), and that the 

 arms are not detlocted. This stage of the lophophore vividly 



