230 



S. J. JOHNSTON. 



The eggs are very small, narrow and pointed at the ends* 

 The largest measured were 0*032 x 0*016 mm., the smallest 

 0*027x0*013 mm., while the average of a large number 

 measured was 0*028 x 0*015 mm. 



This differs from the other species of Harmostomum 

 found in birds, e.g., H. mordens, H. fuscata, H. caudale, 

 and H. centrodes^ in the position and extent of the yolk 

 glands fields, the more median position of the intestinal 

 limbs and the crossing of the uterine coils into the lateral 

 fields beyond the intestinal limbs. All these differences 

 are of course correlated with one another. 



Subfamily CLINOSTOMINiE. 



Olinostomum australibnsb, sp. n. (Fig. 17.) 



Diagnosis. — Large form, widest in the region of the 

 gonads. Oral field well developed. Suckers very large 

 and close together. Intestinal limbs provided with side 

 branches. Genital pore in the middle line. Oirrus sac 

 alongside the anterior testis. Oirrus spiny. 



Host. — Plotus novce-hollandice, in the oesophagus. 



Type specimen in the Australian Museum, No. W. 442. 



Locality, Burnett River, Queensland. 



Two specimens of this species of Clinostomum were 

 obtained from the oesophagus of the Darter, Plotus novae- 

 hollandice, by Dr. Harvey Johnston. One was mounted 

 whole, the other cut into horizontal sections. It is a fairly 

 large form 11 mm, long by 3*25 mm. broad at the widest 

 part, in the region of the gonads. It is fairly thick. The 

 oral field is fairly well marked. The body is constricted 

 at the level of the ventral sucker, and from this point 

 gradually increases in width to the region of the gonads, 

 whence it again becomes narrowed towards the posterior 

 end, which is sharply truncated. The anterior end is also 



