o/" 'rtTfUrafiiliiiii -<jtttMitrii>ii;ili.-:. tl7 



six short and stout cirri, all ot" tlu'in curviiiii; towards the 

 immth, which orciipicd the centre ut" the base tVoni wliich the 

 cirri .spran^^ The dii^estive sae hung tVoni the mouth, and 

 was twice as long as broad, having a strong constriction in 

 tlie centre, t'orniing two chambers, the lowermost one being 

 globuhir in shape and having its walls coloured a light reddish 

 ])rown, this coloured portion evidt-ntly indicating hepatic cells. 

 The cavity next the mouth indicates the stomach, while the 

 lowermost cavity indicates the future intestine or cul-<Ic-sac. 

 The cirri movetl t'retpiently and in various directions, though 

 generally pert'orming a grasping motion, as if securing some 

 bit of food, imitating ])recisely the movement of the cirri in 

 Polyzoa ; and this resemblance was more complete from the 

 fact tiiat the tentacles were densely clothed Avith cilia (fig. 4), 

 and their movements caused visible currents in the water. 

 The two cavities of the digestive sac were also ciliated ; and 

 little pellets of food were seen rapidly circulating back and 

 forth from one cavity to the other. The cavities were alter- 

 nately dilating and contracting. At this stage the lower ca- 

 vity of the digestive sac was diverted to the larger valve, as 

 represented in tig. 4. 



h\ <his stage, and several succeeding stages, the outline of 

 the shall is remarkably like that o{ Lfngula] and this resem- 

 blance is more striking from the proportioiudly long peduncle. 



In another stage, numerous irregular-shaped calcareous 

 spicula lined the outer margin of the cirri, while the future 

 position of the calcareous loop, or crura, was indicated by a 

 row of irregular-shaped s])icula. 



Fig. 8 represents portions of two cirri highly magnified, 

 in which correct outlines are given of the spicula. It is 

 by the presence of these calcareous particles that we must ac- 

 count for a certain rigidity noticed in the texture of the cirri. 

 In these slightly advanced stages the peduncle becomes much 

 shorter in j)roportion to the length of the shell, though tlie 

 shell presents the same Lingi(la-\\\s.Q form, dittering, however, 

 from Limjula in the much greater length of the neural valve, 

 which is always perforated and rostrated from the outset. 



In all these stages the peduncle has very slight adhesion to 

 the rock or whatever substance it may be attached to, in this 

 respect differing greatly from the adult, which often requires 

 great force to detach it, frequently leaving the peduncle sepa- 

 rated from the body and adhering to the rock. 



In side views of the shell at this period (see fig. 5) the 

 flatness of the valves will be observed, again resembling 

 Linyula in this respect ; the under valve is much flatter than 



