DURING HIS SOJOURN IN THE WESTERN PACIFIC. 541 



owiug to the fact that few examples exist in museums, and further because the form 

 of the dorsal fin, the length of the ventrals, the shape and length of the sword 

 appear to change according to the age of the individuals." 



As far as I am aware no Entozoa have as yet been recorded from this eastern 

 sword-fish, the genus is not mentioned in von Linstow's " Compendium der Helmintho- 

 logie " and I have met with no reference to this fish as a host in later literature. 

 The fish is in fact in the adult stage difficult to capture, it is " the largest of 

 Acanthopterygians and not exceeded in size by any other Teleostean " and is unusually 

 strong and fierce. 



The most complete diagnosis of this species B. plicatus is that given by Olsson, 

 which I here copy. 



" Caput ovato-oblongum, apice depressuiii, hothriis oblongis laterulibus. Collurn nullum. 

 Articuli brevissiini, sensiin latiores, murginibus posticis exstantibus, plerumque undulatim 

 crispatis ; aperturae genitalium (?) laterales, marginibus approximatae, vage alternae. 

 Long. 350"""-, lat. max 17, lat. minima 2"""-, long, ovuli Oil"""." 



None of the specimens collected by Dr Willey attained the length of 350 mm. or 

 the breadth of 17 mm. The longest fragment was some 200 mm. and the widest segments 

 were by 3 or 4 mm. broad (Fig. 10, Plate LV.). They break with ease and I have 

 little doubt that if examined alive longer forms would have been found. 



As a rule the head and anterior end of the body are embedded in the mucus 

 lining the intestine, but they are readily detached, the head being but very slightly 

 adherent to the tissues of the host. The anterior end of the head bears a flattened 

 cap divided into four simple lobes (Figs. 8 and 9, Plate LIV.). In the centre of this 

 a slight projection is sometimes seen and is figured by Wagener though it is often 

 absent, but I could not agi-ee to the statement " caput... apice depressum" as universally 

 true. 



The two long slit-like suckers which extend along the head below the cap are 

 situated in a plane which corresponds with the line separating the two lobes of the 

 right side from the two of the left. 



II. CALLIOBOTHRIUM AETIOBATIS, n. sp. 



In his admirable paper entitled "A Cz^paknak es Rajaknak Belfergei'" the late 

 Dr Orley gives the following systematic review of the genera of tape-worms found in 

 the Elasmobranchii. I have ventured to copy the table because, although the Latiu 

 leaves something to be desired, it gives a clear view of the inter-relation of the 

 Cestode genera which infest Selachians and because the Hungarian periodical in which 

 it appears is somewhat difficult of access. 



' Termfszetrajzi Fiixetek, Vol. ix. 1884, p. 97. Budapest. 



72—5 



