379] STUDIES ON GREG ARINES— WATSON 169 



Satellite : 



Length protomerite 50 40 30 



Length deutomerite 450 370 340 



Width protomerite _ _ 90 50 60 



Width deutomerite „ 80 70 90 



Total length sporont '. 500 410 370 



Ratio 



length protom.: total length 1:10 1:10 1:12 



width protom, : width deutomerite 1 :9 1 :1.4 1 :1.5 



Length associations of more 

 than two sporonts 



Primite _..-.. 300 140 120 110 



First satellite : _. 170 150 140 100 



Second satellite 190 140 70 70 



Third satellite 130 



Total length of association 660 560 330 280 



This species is very peculiar in that two distinct types of specimens 

 are encountered, viz, large sporonts SOO/x long associated in twos (asso- 

 ciation 1000/A in length), and very small sporonts 100/x long associated 

 in threes and fours, A chain of three of the smaller sporonts seldom 

 exceeds half the length of a chain of two of the larger type. One chain 

 of four small individuals measured only 560/a long. 



That the two types of sporonts, however, represent a single species 

 is shown by the following facts: (a) one or two of the smaller sporonts 

 are often attached as satellites to a sporont of the larger type ; (b) in- 

 termediate sizes are found between the small and the large sporonts; 

 and (c) the small and large sporonts are identical in shape and propor- 

 tions. Since associations are generally Composed entirely of one type 

 of individuals, the difference is not a sexual one. 



This species is very similar in shape and proportions and the deep 

 concavity of the protomerite of the satellite to Gregarina serpentula 

 de Magalhaes, from Gryllus domesticus. The sporonts of the latter occur, 

 however, in twos, while the former occur in threes and fours and it there- 

 fore belongs to a different genus entirely. 



The species differs considerably from any previously described 

 from the host genus Harpalus. It is differentiated from Gregarina 

 parva (Crawley) Watson, AcUnocephalus gimheli (Ellis) Watson and A. 

 harpali (Crawley) in both measurements and proportions and in the fact 

 that the latter two species are solitary while this one is associative. 



