256 SOME MINUTE ANIMAL PARASITES 



gristle and bone also become diseased, these latter 

 cannot grow much. Movement also is hampered, 

 for the skeleton of the fins, as well as of the head 

 and tail, is commonly affected. Lentospora is far 

 more dangerous to young fish than it is to older ones 

 whose skeletons have become more developed. 



The parasite itself is much like a Myxobolus, but 

 its rounded spore emits an amoebula which differs 

 from all other Myxobolidae in lacking a vacuole that 

 stains with iodine. The trophozoites are large, but 

 owing to their situation are not noticeably motile. 

 Apart from the lack of the iodinophilous vacuole 

 and the remarkable situations in which the organisms 

 occur, there is little to distinguish them from the 

 Myxobolus proper. 



The third genus of the Myxobolidse is known as 

 Henneguya, and while its members occur chiefly on 

 the gills of fish such as the perch and popefish 

 (Acerina), some of its members are able to penetrate 

 the eggs and form cysts within them. The spores 

 of Henneguya are oval, but possess a long, whiplike 

 but rigid appendix at the end opposite the polar 

 capsules. 



The fourth genus, Hoferellus, occurs in the kidney 

 tubules of carp, sometimes in association with Myxi- 

 dium. The organism possesses rather remarkable 

 spores with short horns, somewhat the shape of 

 the egg-case of a dogfish. The sporocyst is striated 

 longitudinally, and the two polar capsules are at one 

 end. It is stated that Hoferellus rarely blocks the 

 kidney tubules, but occasionally stoppage of an indi- 

 vidual tubule is found. 



