MUSEUM OF COMPARATIVE ZOOLOGY. 57 



the latter it differs in not having the upper portion of the column specialized 

 and different fron^ that below, and also in being far less contractile. Urticina 

 differs in not having the large non-adhesive tubercles, the warts, when present, 

 being of the nature of adhesive suckers, and also in having the walls of the 

 body and tentacles highly contractile. Bolocera differs in having the column 

 smooth, or nearly so, with the tentacles long and easily deciduous. Actinernus 

 differs in having the column smooth, and in having the upper margin divided 

 into lobes which run iip on the outer sides of the tentacles. 



Actinostola callosa Verkill. 



Urticina callosa Verrill, Amer. Jour. Sci., XXIII., March and April, 1882, 



pp. 224, 315. 



Plate VII. Fig. 2. 



This is, perhaps, the largest of the eight large species of actinians that in- 

 habit these depths, though A. nodosa, A. longicornis, U. perdix, and Bolocera 

 Tuedice grow about as large. It is also remarkable for the great number of 

 short, stout, usually blunt, striated tentacles. When full grown it has a re- 

 markably firm, thick, leathery, but lubricous integument, and has but little 

 power of contracting or rolling in the upper end. When handled it is apt td 

 become irregularly flattened and collapsed, with, broad longitudinal folds or 

 wrinkles, while the tentacles and disk remain exposed, the ver}^ broad disk 

 usually becomes deeply concave, and the tentacles contract in length and be- 

 come blunt. The body usually narrows to the base, but may be hour-glass- 

 shaped. The surface of the column is usually more or less covered with low, 

 irregular, often flatfish verrucae, wjiich become larger and more prominent, and 

 sometimes form longitudial series or crests on the upper part, but fade out to 

 mere wrinkles toward the base. There is no decided change in the character 

 of the integument near the top, which is a conspicuous character in A. nodosa 

 and A. longicornis. 



The basal disk, in large specimens, is usually bulbous or deeply concave, 

 firmly grasping a large mass of sand' and mud, which it often nearly encloses. 

 In the mud there are often numerous chitinous pellicles, which have been 

 secreted and cast off from the base. 



Large examples are often 150 to 180 mm. in height, -wdth the expanded disk 

 200 to 250'mm. (8 to 10 inches) broad; the larger tentacles are about 25 mm. 

 long, 5 to 6 mm. in diameter. Color generally salmon or orange, all parts often 

 of nearly the same color; column almost always pale salmon or buff, varying to 

 deep salmon or orange-red, with the tubercles paler; disk most often deep 

 salmon, or generally of the same color as the body, but darker in shade, with 

 paler radii; the large lateral lobes of the lips are like the disk, but darker, 

 usually salmon or orange-brown, the large gonidial grooves whitish or pale 

 yellow; tentacles usually plain deep salmon or orange-brown, with paler stride 

 or reticulations. 



