382 ARTHUR T. MASTERMAN. 



outer coils upwards are freely opeu, but iu a section at the 

 very base of the lophophore tbey are seen to be partially- 

 blocked by a pair of large organs, one on eacli side (see fig. 61). 



These problematical organs have had various functions as- 

 signed to them. Caldwell (1) claimed for them a sensory 

 function as indicated by the name '' ciliated pit/' and they 

 have been compared to certain sensory pits in some of the 

 Gephyrea. Mcintosh (12) also observed them in the species 

 under consideration, and noted that they were simple and 

 rudimentary in the young individual. He also noted the 

 presence of mucus in the central cavity of tlie organs. 



Benham (2), working upon Phoronis australis, was led 

 to doubt their sensory function, and considered them to be 

 glandular in nature. He remarked that a similar glandular 

 modification extends as a ridge throughout the lophophore, 

 lying along the face of the inner series of tentacles. I have 

 carefully examined these organs, and ca.n confirm the obser- 

 vations of Benham upon their structure and extent. The 

 " ciliated pit " itself is really only the involuted terminal 

 portion of the ridge of ciliated glandular epithelium extend- 

 ing along the base of the outer coil. Benham has named 

 the whole organ, including the portion extending through- 

 out the length of the outer coil, the " lophophoral gland." 

 My observations of its structure and relationships in P. 

 Buskii do not differ suflSciently from his to justify further 

 figures. 



With regard to the functions of this lophophoral gland, I 

 believe there is sufficient evidence to assume that it secretes 

 mucus, which, driven up the coil by the cilia, forms an 

 adherent surface for the eggs and embryos to be carried in 

 the same direction. Thus these glands would come under 

 the category of subsidiary reproductive organs, or nida- 

 mental glands. 



The proof for this assertion is partly direct and partly 

 indirect. 



Upon dissecting the lophophore, the mucus lying in the 

 gland may often be removed as a long band with a great 



