- 160 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
13. Macrorhynchus naegeli, Kolliker. (Pl. XIII, fig. 21.) 
In form, colour and size this species closely resembles 
the foregoing. It may be readily distinguished, however, 
by the presence of a special chitinous investment round 
the lower portion of the granule-vesicle. his is a short 
funnel-shaped tube, the wide mouth of which is usually 
provided with a curved spur. 
The great bulk of the genital organs in this and other 
species of Proboscide, leads, during the development of 
the individual, to the loss of the alimentary canal as a 
definite coherent structure. Consequently, examination 
of adults shews that the body is almost exclusively filled 
with the reproductive apparatus, the gut bemg merely 
represented by isolated cells. 
This species occurs at Port Erm, Miullport, and 
Plymouth. 
14. Macrorhynchus helgolandicus, Met. (Pl. XI11,fig. 22.) 
During my visit to the Port Erin Station, during October 
of last year I found a number of immature examples of 
this form which is distinguished from all other species of 
Macrorhynchus by the possession of a special ‘‘ poison- 
dart’? in addition to complicated male and female 
copulatory organs. ‘This had led v. Graff to place this 
species in a special division ‘‘ Venenosi’”’ as opposed the 
remaining Macrorhynchus-species included as ‘‘ T'ypict.” 
M. helgolandicus has also occurred at Mullport and 
Plymouth. 
15. Hyporhynchus armatus, Jens. (Pl. XIII, figs. 23, 24.) 
Length 1 mm. Body very elongate, thread-like and 
of a white colour. Although usually associated with 
other Turbellaria of a similar colour and appearance, this 
species 1s distinguished (as they are in turn) by peculiarities 
of locomotion which are sufficient to enable one to 
identify it even with the naked eye. The proboscis (as in 
