STUDIES 0^ THE ECTOPAftASlTiC TEEMATOCES OF JAPAN. 205 



proceeding forwards from the foremost testis dorsally to the uterus. 

 Habitat — Gill of Scomber colias (Jap. Saba). 

 Locality — Misaki. 

 Daie— December 1889. 



2. Octocotijlc minor, n. sp. 

 (PI. IX, figs. 7-13.) 

 Boiy lanceolate, thick, about 2 mm, long, narrow anteriorly but 

 broader posteriorly ; the anterior portion free from the vitellarium 

 long, separated from the hinder part by a slight constriction, and 

 becoming gradually narrower towards the front end. Posterior suclcers 

 small, a little broader than long (being 0.03 mm. x 0.037 mm.), 

 arranged in a straight line parallel to the median line of the body ; 

 the hindmost pair being close to the margin of the body and the 

 anterior ones more removed from it. With two pairs of hooks at the 

 posterior end of the body between the hindmiost pair of suckers ; 

 the outer pair stouter, about 0.037 mm. long (curvature not reck- 

 oned), wholly solid, and with a process near the proximal end ; inner 

 pair filiform and curved, about 0.02 mm. (curvature reckoned). Oeso- 

 phagus longer than in 0. major ; main trunks of the intestine completely 

 separate from each other and reaching the foremost pair of 

 posterior suckers ; each sending out lateral branches both outwards 

 and inwards, the inward branches, however, being very short. Com- 

 mon genital opening midway between the pharynx and the posterior 

 end of the oesophagus. Penis spines long, arranged in six 

 pairs, the foremost and longest ones being curved almost semi- 

 circularly ; each hook consisting of a long, slender, spinous, distal 

 portion and a lens-shaped, basal portion attached to the penis 

 bulb ; diameter '' of the central penis bulb about 0.05 mm., length 



1). Too much specific value must not, however, be placed on these figures ; for in another 



