No. 3-] LOXOSOMA DAVENPORTI. 375 



circulate in a body fluid through irregular spaces in the paren- 

 chyma and perhaps act physiologically somewhat as blood 

 corpuscles. 



9. In the stomach three glandular regions are distinguish- 

 able : {a) paired lateral regions near the lower end of the 

 stomach, composed of elongated, finely granular, ndn-vacuo- 

 lated cells, which stain deeply; (b) the "liver" in the anterior 

 wall, composed of elongated cells containing coarse yellow 

 granules in large vacuoles. 



10. The brain, which is dumb-bell-shaped, is situated in 

 front of the intestine and gives off a pair of nerves from each 

 end. Sensory hairs occur on the surface of the tentacles. 

 Dorsal sense organs are absent. 



1 1 . Proterogynic hermaphroditism occurs in L. Davenporti, 

 ova and later spermatozoa developing in the same gonad. 



12. Gland cells below the commissure of the brain secrete 

 an envelope which surrounds and attaches the developing &^g. 



13. A pair of large gland cells below the brain pour their 

 secretion into the upper part of the oesophagus. 



14. The mammary organ, a structure for the nourishment of 

 the embryo, is formed by a modification of the floor of the 

 atrium between the epistome and the opening of the sexual 

 duct. The developing embryos attach themselves to it and 

 obtain from it their nutriment. 



15. Buds, up to twelve in number, are found attached to the 

 parent. 



16. Imperfect buds are occasionally developed, lacking tenta- 

 cles and digestive organs. They may correspond to vibracula 

 or avicularia of Ectoprocta, and probably indicate the derivation 

 of Loxosoma from a stock-building ancestry. 



1 7. Excretory organs are clusters of large vacuolated cells with 

 ducts to the exterior. They are not provided with flame cells. 



Note. — This paper was accepted by the editor of the Journal in June, 1898, 

 and the drawings for the plates sent to the lithographer at that time. I have 

 recently revised the text, however, making such minor changes as later obser- 

 vations made necessary in so far as this could be done without new figures. 



University of Minnesota, Minneapolis, 

 January, 1900. 



