SPOEOZOA 



43 



when they are called sporonts and live in the open spaces of the organ 

 to the walls of which they have been attached; body in most cases 

 made up of two or three parts (Fig. 65), the epimerite at the forward 

 end, which is the organ of attachment of the cephalont and may be 

 dropped by the sporont, and the body, which may be divided by a septum 

 into the deutomerite which forms the bulk of the body and contains the 

 nucleus and the protomerite which lies between it and the epimerite: 

 about 300 species grouped in 2 suborders. 

 Key to the suborders of Gregarinida: 



a t Gregarines with an epimerite, and with or without a septum between the 



deutomerite and protomerite 1. CEPHALINA 



a 2 Gregarines without epimerite and consisting of a single chamber. 



2. ACEPHALINA 



SUBORDER 1. CEPHALINA. 



Fig. 60Gregarina Watta- 

 rum (Doflein). A, two indi- 

 viduals, each with protomer- 

 ite and deutomerite ; B, cyst ; 

 C, spore. 



Gregarines possessing an epimerite at 

 some stage of their life which is sunk 

 into the walls of the organs of the 

 host in which they live; body usually elon- 

 gate, the animals being often in associated 

 couples or groups arranged tandem, in 

 which case the first individual is called the 

 primite and the others the satellites: in 

 arthropods as adults, especially in the intes- 

 tine of myriapods, beetles and Orthoptera; 

 10 families and about 100 species. 



Key to the families of Cephalina here 

 described : 



a x Spore more or less ovoid 1. GREGABINIDAE 



a 2 Spore not ovoid. 



&! Epimerite asymmetrical 2. DACTYLOPHOKIDAE 



& 2 Epimerite symmetrical. 



c x Spore symmetrical, animal solitary 3. ACTINOCEPHALIDAE 



c 2 Spore asymmetrical. 



dj Spore crescent-shaped ; animal solitary 4. MENOSPORIDAE 



d 2 Spore ovoid with polar thickening ; in marine annelids . . 5. DOLIOCYSTIDAE 



FAMILY 1. GREGABINIDAE.* 



Individuals either associated, forming a chain with a septum sep- 

 arating each two individuals, or solitary; epimerite simple and sym- 

 metrical: 8 genera and about 35 species. 



* See "List of the Polycystid Gregarines of the United States," by H. Crawley, 

 Proc. Acad. Nat. Sci., Vol. 55, p. 41, 1903. "The Polycystid Gregarines of the United 

 States," by H. Crawley, same, p. 632. "Movements of the Gregarines," same, Vol. 57, 

 p. 89. "Study of Some Gregarines," etc., by M. C. Hall, Stud, from Zool. Lab. Univ. 

 Neb., No. 77, 1907. "The Polycystid Gregarines of the United States," by H. Crawley, 

 Proc. Acad. Nat. Sci., 1907, p. 220. 



