34 EMBEYOLOGICAL MONOGRAPHS. 



43. Larva of Hormiphora plumosa, gen. Ag. sp. Sars. gu. Stomach, l.tb. Lateral tube. oaj. Otocyst. 



or. Mouth. si>h. Funnel. 

 a. Embryo of Seroe riifiscens, ¥uTsk. {Forsknlca, C\nm.) l.tb. Lateral tube. ol. Otolitli. Tlie otocyst is not 



yet foiTued about the otolith, or. Mouth. 



45. Larva of the last named, which has reached se.xual maturity, ol. Otolith already enclosed in its otocyst. 



or. Mouth, pig. Pigment. 



46. BcToe roseola, from Agassiz, op. cU. PI. 111. fig. 18. Embryo seen from " abactiual " pole. ol. Otolith. 



17. Eow of vibratilc flappers. 



47. Beroe rufescens, from Chun, op. cil. PI. XIV". fig. 11. Larva seen from one side. aj. Otocyst. 



m\ Mouth, tb. Chymiferous tubes. 



48 50. Bcro'e roseola, from Agassiz, op. cil. PI. III. figs. 10, 20, 22. 



48. Larva somewhixt older than that shown in figure 47, iu which the two chymiferous tubes, under the combs 



nearest the medial line of the figure, have pushed their way to the vicinity of the mouth, ga. Stomach, 

 which occupies the whole body cavity, or. Mouth, r/. Vibratilc flappers. 



49. View of an older larva, seen at right angles to the last. The two tubes, which in fig. 48 were rcjiresented 



as appi'oaching tlie mouth, have in this united, forming a ring about it. The other tubes are advancing to 

 the labial region, ga. The whole cavity of the larva forms a stomach ; the portion marked {ga} one of 

 the tubes of the body walls. aj. Otocj-st. i). Vibrating flapper. 



50. Larva of Beroe roseola, ga. Stomach. cy. Otocyst. 



