122 NEW GYRODACTYLOID TEEMATODES FROM AUSTRALIAN FISHES, 



either been missed, or had dropped off. Wagener's species is stated to possess a 

 single large central hook, but it is possible that the minor hooks have not been 

 observed in this form. In C. inerme, on the other hand, it may be that the large 

 hooks have dropped off, or, as frequently happens in C. glandiilosum, are hidden 

 by the folding of the clasping disc. 



29. Fridehicianella Brandes, 1894. 



Caloeostominae. A rather large species (4 to 5 mm. in length) in which 

 the head-lappets, though prominent, do not attain the extraordinary development 

 seen in Calceostoma. Glandular protuberance on one side of body. Eyes? 

 Ovary not branched. Vagina present. Single testis. Intestine similar to that 

 of Calceostoma.. 



Type and only known species, F. ovicola Brandes, from the eggs of Arins 

 commersonii, a fresh- and brackish-water fish from South Brazil. The male of 

 this fish carries the eggs in its mouth till the emergence of the young, a fact 

 which probably accounts for the carious position recorded for the parasite which 

 we suspect normally infests the gills of its host. 



According to Brandes there is a vitello-intestinal duct present, opening ap- 

 parently on to the dorsal body surface! It seems more reasonable to accept 

 Goto's suggestion (1899) that this is the true vagina, the "Seitenwulst" of Brandes 

 being probably an accessory copulatory organ. 



Appendix to Calceostominae. 



30. C A T H A R I T R E M A, ll.gen. 



In this subfamily is possibly to be included a worm described and figured 

 by MacCallum (1916) as Monocotyle selachii. The remarkable nature of the 

 anterior end and the presence of numerous minor suckers on the adhesive disc 

 seem to exclude the species from that genus. The head-lobes are exceedingly 

 suggestive of Calceostoma, while the "sense-papillae" may readily be regarded as 

 the scattered openings of cephalic glands. If this view be eventually found to 

 be correct, then the genus, for which the name Cathariotrenia is suggested, must 

 undoubtedly be classed amongst the Calceostominoie. Meanwhile, it is simply 

 classed as an appendix to that group. 



Diagnosis : — Rather large forms in which the disc is distinctly broader 

 than the body and is provided with numerous minute suckers. Two large hooks 

 and many minor hooks present. Anterior end provided with large lappets, en- 

 closing the mouth behind. Eyes absent. Intestine bifurcated, devoid of caeca, 

 and ending blindly behind. Testis and ovary simple. Vagina apparently pre- 

 sent. Vitelline system very extensive. Erom the nasal glands of sharks. 



Type, C. selachii (MacCallum, 1916) J. & T., from Carcharias obsciirus and 

 Cestracion sygaena (= Sphyrna zygaena) — from Massachusetts. 



Subfamily II. DIONCHINAE, n. subfam. 



Calceostomidae in which the posterior disc possesses two diminutive major 

 hooks and at times numerous minor hooks. Distinct head-lappets absent. Eyes 

 present. Intestine bifurcated, devoid of caeca. Testis double (see, however, 

 Appendix to Dionchinae). Penis simple. Ovary unbranched. Vagina present 



From the gills of marine fishes. 



Including the genera Dionchus Goto, 1899 ; DioHchotrema, n.gen. ; Lophocotyle 

 Braun, 1896; and possibly Anoplodiscus Sonsino, 1890. 



