683 



The Avorm thus described I have come upon but once in a newt and 

 I am unable to give its exact habitat. It appears, however, to be the 

 same as one I have ah-eady reported (Zool. Anz. Bd. XXV. 

 Nr. 673/674. 1902. p. 482. Nr. 13) although more mature. The de- 

 scription given there (with the decimals corrected) reads: »Encap- 

 suled on muscles in posterior part of body-cavity of Rana virescens 

 at Canso N.S. Length (living) 1,3, breadth 0,6, pharynx 0,12, oeso- 

 phagus 0,15, mouth-sucker 0,21, ventral sucker 0,12 in middle of 

 animal. Coeca to half way between ventral sucker and posterior end. 

 Skin with spines. Immature.« The shape and size of the worm, the 

 relative size and position of the suckers, the intestinal system and the 

 excretory system agree. In the specimens from the frog I was unable 

 to recognize rudiments of the genital system. 



These worms bear many resemblances to Nr. 86 from the snake of 

 Avhich indeed they may be the young. 



66) Cystagora tetracystis Gast. 



Encysted between muscles of throat of Rana catesHana Shaw 



(Bull-Frog). 



Rana virescens Kalm. (Com. Frog). 



New genus: /■yö'rfb', bladder; a/o(>a, assembly. The generic names 

 Agarnodistomum (Stossich) and Distomulmn (Brandes) for immature, 

 agamic, forms are open to the objection that the worms included do 

 not belong to the same morphological type. 



I am not sure that this is the same as GastalcWs species. Until later 

 stages of both and their definitive hosts become known it is impossible 

 to be certain. By analogy, since all the other American forms differ 

 from the earlier known European, one would judge that this also is 

 different (Zool. Jahrb. XIII. 1900. p. 410). 



67) Loxogenes arcanum Nickerson. 



Encysted in liver of Rana catesbina Shaw. (Bull-Frog). 

 New genus: lo^óg, bent sideways, obhgue; ysvc'ao, to produce. 

 This worm was first described by me iDrovisionally under the specific 

 name Distomum medians Olsson (Zool. Jahrb. Bd. XIII. Hft. 5. 

 30. Aug. 1900. p. 412) and almost at the same time by Nickerson 

 a^ Distomum arcanum n. sp. (Amer. Nat. XXXIY. Oct. 1900. p. 811), 

 both comparing it with D. medians. Later (Zool. Anz. Bd. XXY. 

 16. Juni 1902. p. 482) I stated that they are the same but Pratt 

 (Amer. Nat. XXXVI. 1902. p. 959) places them in different genera 

 — Pleurogenes and Brandesia. A renewed study of the subject con- 

 vinces me that not only are they identical but that they must be 

 placed in a new genus. To arrive at such a conclusion it will be 

 neccessary to take a glance at their nearest relatives. 



48* 



