230 



s. GOTO. 



einen ziemlich grossen sitzenden Sangnapf. Derselbe besitzt acht Speichen, von 

 denen die eine in der Längsachse des Thieres gelegen ist, während jederseits drei 

 vom Centram nach der Peripherie hin ausstrahlen. Da wo die beiden letzten den 

 Band des Sangnapfes erreichen, sind zwei grosse, starke Chitinhakeu eingefügt, die 

 in der Querachse desselben gelegen sind. Die Mundöfthnng am vordem Körperende 

 ist sehr weit und dient gleichfalls zum Ansaugen. Die Länge des Thieres beträgt 

 5 mm. bei einer Breite von 2 mm. Der Sangnapf hält 1.5 mm. in Durchmesser. Die 

 Farbe ist weisslich." Later in 1890 Par o na and Perugia'-* published a short 

 anatomical description of the same species, confining themselves, however, from 

 want of materia], to the consideration of the sucker as well as some parts of the 

 genital organs. Many of their statements, however, seem to me so ancmalons and 

 arc in many important respects so at variance with the results of my own studies 

 as set forth in tlie anatomical part of the present paper that I have thought it 

 advisable to base myself only on my own observations in forming the diagnosis of 

 the genus, which I believe I can best embody in what follows : 



Body el(3ng'ated, flattened; with a large circular, sub- 

 sessile, sub-basilar, posterior sucker, the internal surface 

 of which is divided by means of eight radial spokes meet- 

 ing at the centre into as many equal secants. The pos- 

 terior radial spokes lying on each side of the median line 

 carry each a large hook. Moutli large, subterminal, 

 ventral, d e s t i t u te of any sucker. With three teste s. 

 Common iz'enital openini>' ventral and median. Taî^inal 

 opening ventral and lateral. AVith two pairs of eye- spots. 



1. ^Lmocotijlc Ijimae "••, n. sp. 

 (Pis. XVII & XYIII.) 

 Boilij about 3 mm. long, elongated, flattened, but not very broad; 

 posteriorly pointed ; gradually becoming narrower in front and 



1). Parona e Perugia— Di alcuui tromatodi cctoparassiti di posci adriatici. Annali del 

 Mus. Civ. di Storia Naturale di Geuova. Ser. 2, vol. IX, 1890. Estratto pp. 5-8. 



2). Dedicated to Isao Ijima, Ph. D., Ili(jiüxushi, Rhjakuhakushi, Professor of Zoology 

 in the College of Science, Imperial University, Tokyo. 



