44 ILLINOIS BIOLOGICAL MONOGRAPHS [44 



apical papilla. Several chromidial bodies in protomerite. Deutomerite 

 cylindrical, blunt at posterior end. Nucleus spherical with one or more 

 karyosomes. 



Intracellular development noted. 



Intestine and hepatic caeca of Ampdisca spinipes. 



Taken at Woods Hole, Mass. 



Genera of Uncertain Position 

 NEMATOIDES Mingazzini 1891 2nd sem.: 233 



Dicystid, no septum in sporonts, Epimerite forked, at apex of a long 

 neck. "Corpo allungato fusiforme, aguzzo ad entrambi gli apici. Cuticola 

 liscia." 



NEMATOIDES FUSIFORMIS Mingazzini Type Species 



1891 Nematoides fusiformis Mingazzini 1891 : 2nd sem. 233 



1899 Nematoides fusiformis Labbe 1899: 34 



1903 Nematoides fusiformis Minchin 1903:203,329,331 



Characters of the genus. "Trophozoite vermiform, without septum. 

 Epimerite in form of a fork or pair of pincers, borne on an elongated neck." 

 Minchin. 



Intestine of Balanus perforatus, Pollicipes cornucopia. 



Balanus sp. also harbor Cephaloidophora communis Mawr. and Pyxin- 

 oides halani (Kolliker) Tregouboff . 



Mingazzini says the new species above is the Gregarina halani of 

 KoUiker. But the cephalont depicted by Kolliker corresponds in every 

 particular with that of an early cephalont of Pyxinoides balani. See dis- 

 cussion under that species. 



If, however, the fully developed epimerites of the two species, Pyxin- 

 oides balani and Nematoides fusiformis are considered, they are suspiciously 

 similar. Labbe emends the original description of the latter thus: 

 Epim. en forme de fourche ou de pince, 

 separe par un col allonge du reste du corps. 



The only character, then, in which the two species differ is this: The 

 latter possesses no septum in the sporont and is in appearance a Monocys- 

 tid, while the former has a complete septum in all stages except the very 

 earliest. Exhaustive researches may contribute something upon this 

 point and prove the two species identical. 



Below is the original description of the species: 



Cercando ndl'intestino del Balanus perforatus la Gregarina balani der Kolliker che € una 

 policistidea, ho trovato invece una monocistidea appartenente a questo gruppo di gregarine 

 vermiformi. £ pittosto lunga, ha la membrana intieramente liscia, un nucleo ovale al centre 

 con un nucleolo. Sembra assai rara. L'apice anteriore, troncato, termina con una specie di 

 ventosa, il posteriore invece e affatto puntuto. Nell'apice anteriore vi e un po'di metaplasma, 

 net resto vi ha I'endoplasma. 



