158 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
shaped, and consists of a number of chitinous pieces, 
separating the duct of the vesicula seminalis from the 
passages constituting the outlets for the granule-eland, 
The sperm, conveyed down the main duct, issues through 
the passages{ tf, the granule-secretion on the other 
hand by the duct marked { t, outside the retort. The 
chitinous strips forming the neck, are bound together by 
the piece marked D. The spermatheca, placed in front of 
the genital pore, receives at its blind end the chitinized 
ducts of an accessory-gland, while its distal portion bears 
a series of five triangular chitinous teeth hinged at their 
bases to its inner wall. 
This species occurred in tide-pools round Port Erin and 
also commonly among weeds from “the Clets” a group 
of rocks in the Calf Sound. It has been recorded from 
Millport and Plymouth. 
Family—PROBOScIDA. 
11. Pseudorhynchus bifidus, M‘Int. (Pl. XTV, figs.33, 34.) 
Length 1 mm. Body produced in front into a conical 
non-ciliated ‘‘ proboscis’; posteriorly it widens and ends 
in a bifid hinder extremity. Colour whitish-yellow with 
rounded brown spots over the surface. This form is 
interesting as 1t shows the way in which the proboscis 
characteristic of this Family has been elaborated. In 
Pseudorhynchus the proboscis is simply the shghtly modi- 
fied anterior extremity, furnished with numerous short 
retractor muscles. It is probable that by a specialization 
of these together with the addition of a mass of muscles 
known as the “muscle-cone”’ and a pharyngeal sheath, 
the typical proboscis has been formed as we see it in e.g. 
Acrorhynchus. 
The copulatory-organ is a long funnel -shaped chitinous 
structure, round the outer face of which a spiral ridge 
