98 ART. 4. — N. YATSU : 



septentrionalis Couth. ('73 a) is most important, as it is based on 

 a fairly complete series of developmental stages. 



In the same year Kowalevsky ('73, '83) published his 

 epoch-making work to which we owe our most precise and 

 valuable information regarding the early history of Brachiopod 

 development. His well known observations cover the embryonic 

 development of four genera ; viz. Cistella {Argiope), Lacazella 

 (Thecidium), Ter ebr alula and Terebratulina. 



Five years later Brooks ('78) studied the free-swimming larva? of 

 Glollidia pyramidala Stimp. His material was taken in the vicinity 

 of Fort Wool in the Chesapeake Bay during the summer of 1877. 

 As already stated this is the only work on the embryology oîLingula. 



Van Bemmelen ('83) in his anatomy of the Testicardines, 

 expresses the opinion that internal fertilization cannot occur among 

 Brachiopoda and that the egg shows no trace of yolk, being 

 holoblastic and the cleavage being regular. 



Shipley ('83) obtained various developmental stages of Cistella 

 neapolitana Scacchi in Naples, and studied them in connection 

 with the adult anatomy. In the main his results verify those 

 of Kowalevsky. 



Schulgin ('84) confirmed Kowalevsky's observations in 

 Cistella neapolitana Scacchi {= Argiope kowalevshil Schulgin) 

 on the formation of the mesoblast (p. 124). Further he remarks 

 (p. 138) that the seeming segmentation in the larva of Cistella 

 is not a true one, but is due to mere folds of the skin. 



JouBiN ('86) gives a brief account of the embryonic Discina 

 in two places in his paper. He found an egg (p. 264) of the 

 2-cell stage between the cirri. The cleavage was unequal. At 

 another time he saw a small body in the oviduct, which he with 

 some doubt referred to as an embryo. It is in my opinion very 



