ELLOBIOPSIDAE 307 



surface of the organ of fixation in Page's specimens in reality was the proximal part of the root 

 system with its intricate trabecular mass of cuticular matter, bringing about a pronouncedly uneven 

 surface of this part of the parasite. . 



The six specimens of Pasiphaea tarda Kroyer from the Skagerrak infested with Amallocystis capdloms 

 Fage were all of the male sex. Curiously enough the two specimens of Pasiphaea acutifrons Bate from 

 the Strait of Magellan bearing the same parasite are both females. They do not show any mdication of 

 differences from normal females, as might be expected as a result of the parasitization. As, however, no 

 material of uninfested specimens of this rare species was available, it is not altogether certam that m 

 every respect they are of normal appearance. 



Fig. x6. Amallocystis capUlosus Fage, specimen of Figs. X.-15. «. detail of fig. 13, further enlarged Mieve plate of section 

 between those of Figs. 13 and 14. /, organ of fixation; /.., proximal root system; ., sieve plate, x 190. 



THE CHARACTERS OF THE SPECIES OF THE GENUS AMALLOCYSTIS 

 A synopsis of the characters of the described forms of the genus Amallocystis, based on data from the 

 literature and on those of the present paper, shows the foUowmg particulars. 



(i) The parasite mentioned and figured by Bate (1888) 



Hostandmannerofattachment:P««>W.m/a^a Bate, ventral surfaceofsecondabdommalsegnient. 



Number and arrangement of trophomeres: Approximately fifty (?), in a bundle spreadmg from 



a common centre. , ,. , • 1 • 1 * • 



Shape of trophomeres and gonomeres: Trophomeres elongately cyhndncal or conical, twice or 



2| times as long as broad; gonomeres globular to oval. 

 Number of gonomeres on each trophomere: Three. 



Dimension of gonomeres : Unknown. 

 Organ of fixation : Unknown. 



(2) Amallocystis racemosus (Coutiere) 



Host and manner of attachment: Pasiphaea tarda Kroyer, ventral surface of third abdominal segment. 



Number and arrangement of trophomeres: About fifty, in a single bundle attached to a common 

 basal organ of fixation. Total length of the trophomeres with their gonomeres up to 4 mm. 



O 21-2 



