30 VERRILL ON THE POLYPS OF THE 



lamellae ; upper portion covered by prominent suckers arranged in a vertical row along 

 each ambulacral space, each one situated in the centre of a little square. Tentacles 

 twenty, slender, with rounded knobs at the ends. They are arranged in three cycles 

 forming six systems, but in two of the systems next to one end of the anterio-posterior 

 axis, the tentacles of the third system are wanting. Those of the first and second cycles 

 in the perfect systems are nearly equal, and about double the length of those of the third 

 cycle ; in the imperfect systems those of the second cycle correspond in length to those of 

 the third in other systems. 



Color of the column light brownish yellow ; tentacles lighter, the knobs at the tips dark 

 brown. 



Average length in expansion, about 3 inches ; thickness, .40 ; length of tentacles, .25. 

 (Coll. Mus. Comp. ZoGl.) 



Long Island Sound, shores of Nantucket, Martha's Vineyard, and Cape Cod, buried to 

 the tentacles in sand near low-water mark. 



This species is closely allied to the following, and like it is remarkable for its great size 

 compared with the European representatives of the genus. From H. producta it differs in 

 having larger and less numerous suckers, which extend lower down on the column, and in 

 the knobbed character of the tentacles. It appears to be quite common in its localities. 

 According to the observations of Dr. Stimpson and Mr. B. T. Morrison, it occupies in ex- 

 pansion the whole length of its burrows, which are sometimes a foot deep, and can contract 

 and withdraw itself to the lower end when disturbed. In some instances the base was 

 found to be adherent to a small pebble at the bottom of the hole. 



Halcampa producta Stimpson, MS. 



Actinia producta Stimpson, Some Remarkable Marine Invertebrata inhabiting the shores of South Carolina, Proceedings of the 

 Boston Society of Natural History, v. p. 110 (1856). 



Plate I. figures 10, 11. 



Column in expansion very long, somewhat claviform above, slender below, in contraction 

 cylindrical, often constricted. Base capable of distension, and of adhering to pebbles or 

 shells beneath the surface of the sand or mud in which it burrows. The surface of the 

 body is marked by twenty longitudinal sulcations, corresponding with the internal lamella? 

 and continuing to the centre of the base ; the upper portion, for about a third of the whole 

 length, is covered by numerous prominent suckers arranged closely in rows along the am- 

 bulacral spaces, the upper ones largest, decreasing downward until they become obsolete 

 near the middle. " Tentacles twenty, short, stout, enlarged and rounded at the ends, which 

 are covered with white dots. Five of these tentacles usually stand erect, the remaining 

 ones curving over and alternating by threes with the erect ones. The animal retracts its 

 tentacles very slowly when disturbed." 



Color of the column transparent yellowish green. Length in contraction about 3 inches, 

 diameter, .75 ; in expansion probably 8 or 10 inches, since the base was found attached at 

 that distance below the surface. 



Near Fort Johnson, S. C. Found in considerable numbers buried in the mud on the 

 flats near low-water mark. Its position is indicated, after the tide has retired, by little 

 cracks on the surface of the mud, which radiate from a small central hole. 



This interesting species, the largest described of the genus, is known to me only through 



