538 Prodromus of the 



tuft; the three in the distal transverse rowpistiHlform, i. e., 

 the distal side of tlie three tentacles is considerably thick- 

 ened by the development of a layer of adhesive vesicles, 

 but not to such an extent as to disguise their tentacular 

 nature, united at their bases for one quarter of their 

 length, as if a triple organ ; the length of the largest ten- 

 tacles is to their thickness as eight is to one, the length of 

 the pistilliform ones is to their thickness as five is to one ; 

 the terminal knob globose, slightly depressed at the end, 

 as broad as the base of the tentacle : marginal anchors 

 reverted, very small, one third as long as the pistilliform 

 tentacles, but proportionately thicker, their length being a 

 little less than three times their radial diameter, i. e., from 

 the distal to the proximal side, and a little less than twice 

 their lateral diameter ; the layer of adhesive vesicles nearly 

 of uniform thickness from the knob to the base where it 

 rather abruptly thins out ; in the pistilliform tentacles this 

 layer is thickest midway between the base and the knob, 

 and gradually thins out each way; in both anchor and 

 pistilliform tentacles it occupies the distal two thirds of 

 the circumference ; the knob of the anchor is proportion- 

 ately much smaller than that of the tentacles : genitals 

 transversely fifteen to seventeen times folded, ligulate 

 bands, which extend from their point of union, at the prox- 

 imate end of the partitions, to the inner edge of the mar- 

 ginal muscle, the folds or lobes gradually enlarging toward 

 the distal end ; each of these lobes constitutes a single 

 genital saccule ; the digitiform bodies, in a single row, 

 very far apart, extend from near the proximal end of each 

 band a little more than half its length : the horizontal 

 membrane which forms the claustrum in which the genital 

 bands are confined is excessively thin and very extensible : 

 pedicel muscles four very thin cords, not easily detected 

 on account of their transj^arency, imbedded in the gelati- 

 niform mass, between the distal corners of the cameras : 



