70 GRIFFIN. 



having a number of small blue spots, 1 millimeter or less across, 

 about the bases of the rhinophores. The smallest spots are 

 entirely blue, but the larger and more usual ones have dark 

 centers, marked and colored like the general surface of the 

 body. Each spot is finely margined with black, outside of 

 which is a second equally fine ring of gray to brown. 



In certain lights, the foot shows a beautiful violet iridescence, 

 possibly due to the layer of mucus covering it. During life, 

 the gizzard, hermaphrodite gland, and anterior genital mass 

 show through the tissues of the foot. The expanded oral surface, 

 the ventral edges of the oral lobes, and the groove separating 

 the head from the foot are very lightly pigmented. 



The parapodial lobes are separated for more than half their 

 length by the branchial fissure, but fused with each other poste- 

 rior to this (fig. 1, Plate I) . At the level of the anterior end of 

 the branchial fissure they are joined to the body wall from the 

 seminal furrow to the margin of the foot (fig. 8, Plate II). A 

 large contractile sac is thus formed which surrounds, but is not 

 attached to, the visceral mass of the body, within which lies the 

 large branchia, and into which open the anus and the renal and 

 reproductive pores. The branchial fissure lies slightly to the 

 right of the median dorsal line. During inspiration, the anterior 

 end of the branchial fissure (inhalent siphon) expands, and its 

 margins are elevated, while the posterior extremity closes. The 

 parapodial sac enlarges so as considerably to increase the space 

 between its wall and the body. When expiration begins, the an- 

 terior opening closes suddenly, the posterior (exhalent siphon) 

 opens, and the water inclosed by the parapodial sac is expelled by 

 the contraction of the walls of the sac with considerable force, a 

 force sufficient to carry all refuse well beyond the end of the tail. 

 The anal papilla lies immediately below the exhalent siphon (fig. 

 8, Plate II). It can be extended so as to bring the anus almost 

 into the exhalent siphon (fig. 9, Plate II) and thus discharge 

 faecal materials into the outpassing current in such a manner 

 that they will be completely carried away. 



The division between the right and left parapodia is main- 

 tained anteriorly by the seminal furrow, which passes from the 

 genital orifice over the dorsum and right side (fig. 8, Plate II), 

 to the penial pore, just below the right tentacle. 



The body wall, parapodial lobes, and foot are translucent and 

 appear to be composed largely of a gelatinous connective tissue. 

 There is present, however, a considerable amount of muscle tissue 

 in these parts, and they shrink little in properly preserved speci- 



