ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



59 



genus, Acanthatrium^ is established for Lecithodendrkcm sphserula Looss, 

 and for a new form {A. nijcteridis) found in the intestine of a bat 

 {Nycteris Urealis) in Illinois. The genus includes small-sized Brachy- 

 coeUinae, spherical to pyrif orm, with a genital atrium lined with numerous 

 integumentary spines ; prostate glands numerous ; testes pre-acetabular^ 

 in a plane with the genital pore ; vitellaria anterior to the digestive 

 caeca ; excretory system with four groups of flame -cells of three each for 

 each half of the body. The fourfold grouping may be a common 



The excretory system of Acanthatrium nycteridis g. et]sp. n. 



The natural size of the fluke is 0-185-2 mm. in length by 0- 15-0- 16 mm, 



in breadth. 



denominator of the several sub-families of the Brachycceliid^e. From 

 the genus Lecithodendrium it is necessary to separate off another new 

 genus, Mesodendrium, for L. granulosum, L. hirsiitum and X. imia. 



J. A. T. 



Coelentera. 



Development of Sea-anemones. — James F. Gemmill {Phil. Trans.,. 

 1920, 209, Series B., 351-75, 3 pis.). A study of 3Ietridium dianthus 

 and Adamsia palliata. Segmentation is equal or subequal, from the first 

 in J/., beginning with the 4-celled stage in A. There is a bilaminar,. 

 greatly folded, and subsequently often saucer-shaped pre-blastula stage 

 in A. The blastulge are spherical hollow in J/., filled in A., with a 

 central non-nucleated or sparsely nucleated trophic mass, produced by 

 constriction of the inner yolky ends of the cells of the blastula wall. In 

 both M. and A. embolic gastrulation occurs, sometimes assisted by uni- 

 polar cell proliferation, and in A, the central trophic material gradually 



