On a new Polycystic! Gregarine, 

 Spirosoma caudata nov. gen. et nov. sp., 

 from a Diplopod. 



By 



Shigemi Jshii, Rigakushf. 



With two figures. 



In examining specimens of Foiitancria coarciata Pocock preserved in 

 alcohol, which were collected on Mt. Kinkazan in Gifu, I have discovered 

 numbers of a curious gregarine showing conspicuous spiral striation in the 

 posterior parts of body. I regard the form to represent a new genus and 

 species, which I shall call by the name of Spirosoma con iata. 



Spirosoma caudata* n. g., n. sp. 



Sporonts always solitary. The entire body, up to 400 p. in length, 

 consists of a broad anterior part, prolonged posteriorly into a narrow tail- 

 like part. 



Protomerite short, usually a little broader than long ; generally conical, 

 sometimes somewhat pentagonal in lateral view. Fully developed adults 

 frequently show a shallow depression on the sides of protomerite. In the 

 young the protomerite is relatively large, and usually a little longer than 

 broad ; there is no depression on the sides ; the anterior end is narrower 

 than in the adult. The smaller sporonts exhibit a pore-like structure at 

 the apex of protomerite, while the larger sporonts either show it but very 

 inconspicuously or are entirely without it. From the presence of the 

 pore-like structure if only in the younger stages, and also from the fact of 

 the host being a diplopod. I should place the gregarine in the family 

 Stenophoridae Léger & Duboscq. 



Deutomerite large and elongate ; divisible into two parts, the broad 

 anterior and the narrow posterior The anterior part is usually of an ovoid 



