650 F. F. LAIDLAW. 



intermediate between the Mesostoiuidge and ProboscidcU. It 

 is particularly of interest as being the only member of either 

 of these families that has adopted an epizoic habit. 



The character of the parenchyma should be specially 

 remarked. This, in the way in which it merges into the 

 endodernij shows a distinct approach to the condition found 

 in the Alloiocoela. 



The genus Typhlorhynchus may be defined briefly as 

 follows : 



Body provided with a non-retractile pre-oral lobe or 

 proboscis. Gut not clearly separated from the parenchyma, 

 provided anteriorly with a median diverticulum extending 

 into the pre oral lobe. Pharynx rosulate, no genital atrium, 

 male opening in front of female. Penis (when evaginated) 

 with meridionally arranged rows of spines, and in addition a 

 long chiiinoid tube. The single pair of testes lie in the 

 pre-oral lobe; ovary single, at hind end of body ; yolk glands 

 paired. Accessory female organs consist of — (1) a bursa 

 seminalis opening to exterior by the female aperture; (2) a 

 receptaculum seminis. 



In conclusion, I wish to thank Dr. Gamble very sincerely 

 for the kind way in which he has assisted and advised me in 

 preparing this account. 



Literature. 



1. Jensen, Olaf S. — ' Turbellaria ad Litora Norveii^ia} Occidentalia, 



Bergen, 1878. 



2. Gkaff, von. — ' Monograpliie d. Turbellarien. I. Ehabdocoeliden,' 1882. 

 3 BoHMlG, L. — "Untersucli. ii. rhabdocoele Turbellarien," ' Zeits. f. wiss. 



Zool.,' li, pp. 167—479, 1890-91. 



4. Gamble, F. W. — " British Marine Turbellaria," this Journal, April, 1893. 



5. DoRLEii, A. — " Neue u. wen'vj; bekanute rhabdocoele Turbellarien," ' Zeiis. 



f. wiss. Zool.,' Ixviij, 1900, pp. 1—42. 



