and on the Mammaria Manhattensis. 91 



Explanation of Plate 3.. 

 Fig. 1. Represents : Molgula Manhattensis, of natural size. 



2. The test has been removed ; left, or neural side. 



3. Test removed ; right or haemal side. 



4. Mammaria with embryo ; test removed. 



5. Larvae, Diam. 300. 



6. Piece of the branchial sac. 



Explanation of Lettering. 

 b. t. Branchial tube, with six-lobed orifice. 



a. t. Anal tube, with four-lobed orifice, 

 n. g. Nervous ganglion. 



n. r. Nervous ring. 



b. s. Branchial sac. 



c. s. Circular sinus. 



b. V. Branchial bloodvessels. 



s. Stomach. 



1. Liver. (?) 



i. Intestinal canal. 



r. Rectum, 

 cl. Cloaca. 

 1. o. Left ovary. 

 r. o. Right ovary. 



h. Heart. 

 s. c. Saccus calcareus. 



c. Calyx, 

 ov. Oviduct. 



p. Pericardium. 



s. Sediment in the Saccus calcareus. 

 f. m. Fibrous membrane, 

 cm Circular muscles, 

 t. m. Transversal muscles. 

 1. m. Longitudinal muscles. 



e. Embryo, 

 f. c. Fat cells, 

 r. o. Rudimentary organs enclosing the heart. 



