MICROT^NIELLA CLYMENELIwE, A NEW GENUS 

 AND NEW SPECIES OF COLONIAL GREGARINES. 



GARY N. CALKINS. 



While examining the gut contents of marine annelids at Woods 

 Hole during the month of June, 1914, a number of new gregarines 

 were discovered. The majority of these were ordinary types 

 which could not be placed systematically without knowledge 

 of the sporulation stages. One form, however, found in the 

 digestive tract of Clymenella torquata, deserves mention because 

 of its remarkable novelty. 



To obtain the material, the worms were opened along the mid- 

 dorsal line; sections of the digestive tract about half an inch 

 long, were removed and teased in salt solution on cover glasses. 

 The material thus prepared was examined while fresh, and, if 

 interesting, was then fixed in sublimate acetic and stained. In 

 this way I have obtained more than a hundred specimens of the 

 curious organism described here. 



The name Microtceniella is given because of the Taenia-like 

 structure of the organism (Figs. 1-5). The initial single cell 

 resembles a scolex and the chain of cells, formed partly from the 

 initial cell and partly by cell division of the daughter individuals, 

 resembles a chain of proglottids. In sporozoan terminology 

 these may be termed the primite and satellites respectively, 

 although this involves some elasticity in the use of the terms 

 primite and satellite which are usually employed to designate the 

 primary and secondary individuals in a chain of gregarines formed 

 by secondary association. 



In the living state, the organism is colorless but with the char- 

 acteristic dense protoplasmic structure of the gregarines. The 

 average dimensions of the chain are 84 /JL in length and 15 n in 

 width, the size of mature chains varying but little from the 

 average. 



The earliest stage found was an initial cell with two nuclei 



and the beginnings of a septum cutting off a first satellite (Fig. i). 



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