D. BRYCE ON MACROTRACHELOUS CALLIDIN^. 453 



agglomeration of drift particles, in which one failed to detect the 

 presence of any secretion from the tenant. The tube made by 

 Call, eremita is undeniably mainly composed of a secretion, for 

 if forced by circumstances to abandon its tube or case the Callidina 

 will, in the live box and in the course of a few days, develop 

 around it a delicate investment, which is gradually increased in 

 density until it is recognizable as a perfect case. The form is that 

 of a somewhat flattened flask, which is attached to the moss leaf or 

 stem by that side which protects the ventrum. The neck of the 

 flask fits somewhat tightly to the first central when the animal is 

 extended or feeding, and is there somewhat viscid, as is evidenced 

 by a cloud-like mass of drift particles adliering to it. It also 

 adheres to the skin, so that when the animal withdraws from view 

 the anterior edges of the case are drawn inwards and the opening 

 closed. The case is usually only just large enough to contain the 

 Ilotifer when retracted ; sometimes, however, an e^g could also be 

 seen in the cavity. I could detect no trace of structure, but noticed 

 only a somewhat plentiful sprinkling of minute and more solid- 

 looking points. 1 conjecture, however, that the material 

 employed would probably be identical with that employed by 

 the Callidin?e generally for the "varnishing" of their trunks 

 when they fear deprivation of water. I believe, too, that it is 

 mainly secreted while the animal is retracted, a position which 

 my specimens would retain frequently for hours. When desired 

 it was usually easy, however, to induce them to display their 

 wheels; the introduction into the live box of a drop of clear 

 cold water was very effective. Then instinct prevailed over 

 modesty, and out would come the Callidina to sample the current 

 food supply. The head and neck once protruded, usually at right 

 angles to the trunk, the discs were promptly displayed and the 

 cilia vigorously exerted. The hii;h diverging pedicels give a very 

 distinctive character to the corona, and equally striking is the bold 

 curvature of the upper lip, which is apparently nowhere in contact 

 with the pedicels, but stands back so that their common fleshy 

 base is visible. Centrally between the pedicels stands a short 

 setiform fleshy tooth. Thus outstretched the head and neck are 

 nearly as long as the trunk, and the bizarre appearance of the 

 swollen central trunk is increased by the first central segment 

 which occupies the neck of the flask being slender like the 

 head and neck. The mastax is of good size. Besides the three 



