'ITPHLORHYNCHUS NANUS. 639 



to create a new genus for its reception under the name of 

 Typlilorhynchus. The species may be called Typhlo- 

 rhynchus nanus. 



Habits. — Typlilorhynchus nanus, as already stated, is 

 found on the body of Nephthys scolopendroides, to 

 which it attaches itself by its hinder end. From Mr. Good- 

 rich's figures (figs. 2 a — c) it appears to use its proboscis as 

 a tactile organ. In no specitnen that I have examined is 

 there any food substance in the gut space, but in the proto- 

 plasm of the gut wall are numerous fine food granules. Its 

 epizoic habit does not seem to have produced any marked 

 degeneration of the organs of the body. The loss of the eye 

 may be due to this, but a number of species belonging to the 

 genus Mesostomum which are free-living* {e.g. M. Ouenoti, 

 recently described by Dorler [5]) are also without eyes. 



The other known parasitic Rhabdocoeles belong to the 

 family Vorticidse, and include a number of forms parasitic 

 in Echinoderms, on the kidneys and gills of Molluscs, etc. 



Method. — Mr. Goodrich obtained specimens of Typhlo- 

 rhynchus by putting Nephthys scolopendroides into 

 sea water with a})out 10 per cent, of alcohol (70 per cent.), 

 when the parasite fell off in considerable numbers. No eggs 

 were found. They were then treated with corrosive sub- 

 limate and acetic acid or with Lang's reagent. Those 

 treated with the latter yield on the whole the best results in 

 sections, the protoplasm being beautifully preserved. Those 

 hardened with the former reagent have shrunk to some extent, 

 but in tliem the gland cells and rhabdites stain more readily. 

 I have examined a number of series of sections both trans- 

 verse and longitudinal, as well as specimens mounted whole. 

 For the sections I obtained excellent results with brazilin ; 

 I also employed the iron-hasmatoxylin method of staining. 

 Whole preparations were stained with borax carmine. 



Structure: Integument. — The body-wall is made up of 

 a layer of ciliated epithelium lying upon a double muscle 

 layer. The epidermis is equally ciliated over the whole 

 surface of the body. A number of irregularly arranged 



