138 PEOP. OWEN ON NEW AND EAEE CEPHALOPODA. 



in the usual alternate disposition (PI. XXVI. fig. 1, i, 3). The dorsal pair (1) of arms are 

 the shortest and most slender ; the third and fourth (ventral) pairs are the longest and 

 thickest. Only the basal part of the stem of the left tentacle, p, remains in the specimen 

 described. 



On each side of the base of the funnel is a narrow elongate cartilage, q, excavated for 

 the reception of a cartilaginous prominence, r, of similar form, from the juxtaposed 

 inner surface of the muscular mantle. The infundibular tube is shown slit open along 

 the ventral wall, exposing the terminal valve, s. The masses of the " musculi retractores 

 infundibuli " are shown at t, t. The anterior or descending aorta, «, is drawn from 

 the intervening recess of the above muscles. The posterior aorta has been removed near 

 its origin, v. The systemic ventricle is transversely elongate and bent at a right angle, 

 as in Sepia. 



The vena cava, w. is partly withdrawn from the intermuscular recess ; and its two 

 divisions, with their glandular tunics, are shown diverging to the lateral branchial hearts, 

 X, X, each of which has a small fleshy appendage. The margin of the gill lodging the 

 branchial vein is shown at y. The trunk of each vein enters the contiguous end of the 

 transverse ventricle, the right rather more advanced than the left. The branchial lamellae 

 are narrow and numerous. 



The digestive viscera, agreeing closely with those of Sepia, have been removed to bring 

 more clearly into view the circulatory, respiratory, and generative organs. A part of the 

 liver, with its peritoneal capsule partially reflected, is shown at s. 



The testis, a, occupies a peritoneal compartment at the hinder end, or fundus, of 

 the abdominal ca^dty ; on removing the serous coat, as in the figure, the fibrous 

 tunic is exposed. To a part of the inner surface of this membrane are attached the 

 seminal tubes, which diverge and branch dichotomously, filling the cavity, and ter- 

 minating blindly. They are bathed in the seminal fluid, which escapes by rupture of 

 the tubules into the fibrous sac, whence it escapes by a foramen leading to a long, 

 slender and tortuous " vas deferens." This tube opens into a larger one, the size of 

 which is chiefly due to the thickness of its fibrous and glandular parietes, which present 

 narrow transverse plicse toward the cavity of the present canal, which has been termed 

 a " vesicula seminalis : " it is shown at c. The anterior end of the " vesicula " 

 communicates with a second, oblong, blind glandular sac (ib. d) : it has been compared 

 to a "prostate gland." Without sanctioning such homologies with the parts so called 

 in the mammalian class, it is certain that the seminal fluid or spermatozoa are packed into 

 capsules, contributed by the glandular parts of the above accessory organs, the capsules 

 being therein moulded into the filamentary form. These " spermatophora " are con- 

 veyed by a short and wide duct to an oblong pouch, /, sometimes called (after the 

 naturalist and theologian who first drew attention to the moving powers of the fila- 

 ments) " Needham's pouch " [bursa Needhami). A short canal conducts the spermato- 

 phores to the base of the penis, h. 



