51 



through the outer wall into the ocean, and I have seen them, with 

 the broadest end out, pi'ojecting like bundles of hairs from the cav- 

 ity of the matrix through the apertures in the outer wall. When 

 the reproductive material is fully ripe, the inner wail, with the gela- 

 tiniform layer, and the muscular layer as far as it includes the mate- 

 rial in question, splits off from the outer wall along two lines corres- 

 ponding to the two borders of the generative organ, and hangs 

 loosely, in ribbons, in the digestive cavity. From the newly-formed 

 raw face of these ribbons the eggs or spermatic particles escape into 

 the main chamber of the disc. This I take to be the universal rule, 

 and such the type of genitalia among all Steganophthalmata ; a struc- 

 ture totally unlike that of Lucernaria, in which the inner wall alone 

 is concerned in the highly complicated reproductive organs. 



Passing now to the consideration of the muscular system, I will call 

 your attention to the four white, slender columns which alternate 

 with the four dark tubes which are imbedded in the gelatiniform sub- 

 stance of the peduncle. Sars was the first to indicate the true na- 

 ture of these columns, and he rightly called them muscular cords 

 They extend from the base of the peduncle to the base of the pro- 

 boscis, coursing along just beneath the outer wall, but still within the 

 gelatiniform substance, until they reach the upper third of the pedun 

 cle, and then gradually approximating the axial line, they meet the 

 inner wall of the disc just below the base of the proboscis, and thence 

 they pass along still beneath this wall, for a short distance, and, finally 

 each one enters the oral side of the disc at the inner or axial end of 

 the partition. At this point, each muscular column expands and 

 forms a fan-shaped layer just beneath the outer wall, and extends lat- 

 erally so as to occupy the whole space between the two halves of a 

 genital. At the distal end, this layer diverges right and left of the 

 partition into a broad muscular band which borders the disc, and, 

 eventually, is distributed in ridges or cords beneath the outer wall of 

 the tentacles and the auricles. At the inner end of the partition, the 

 muscular layer also passes into the base of the proboscis, and forms a 

 stratum immediately beneath the outer wall. At four equidistant 

 points, alternating with the partitions and genitals, and opposite the 

 four corners of the proboscis, there is a weaker muscular layer, which 

 occupies the same relative position in regard to the outer wall as does 

 the stronger system of muscles first mentioned. On the one hand, it 

 passes into the marginal muscular band, and on the other it enters 

 the corners of the proboscis, and forms a layer in common with the 

 one extending from the partitions. By these alternating stronger and 

 weaker divisions of the muscular layer, the disc is relieved of the 

 sameness which prevails in the muscular system of the Steganoph- 

 thalmata, and we have Indubitable proofs of a higher degree of special- 



