PELTODORIS GREELEYI MAC FARLAND 85 



series of short, rod like spicules which are continued up into 

 the papilla to its summit. The minute papilla, which lend to the 

 surface of the dorsum its velvety appearance, are supported by 

 a large number of spicules, distinguishable into two classes. In 

 the axial portion of each papilla are found four to eight stout, 

 blunt, cylindrical spicules at right angles to the general body 

 surface. Placed obliquely around these in a radiate manner, 

 their central tips forming a close ring at the summit of the 

 papilla, are a variable number of more slender, pointed spicules 

 of the type generally found throughout the thickness of the 

 integument (PI. XV, fig. ^j). The average length of the central 

 spicules is 0.07 mm., their diameter 0.006 mm., while the oblique 

 spicules average o.ii mm. in length and 0.004 """ti- i" diameter. 

 The pseudo-peritoneum is colorless throughout, all the viscera 

 being covered with a delicate sheet of connective tissue. Loosely 

 attached to the dorsal surface of the central nervous system is the 

 bilobed blood gland, very thin and flat, its anterior lobe being 

 much smaller than the posterior one. 



Alimentary System. 



The oral tube is short, broad and muscular, 1.25 mm. long 

 by 1.75 mm. wide, partly everted through the mouth opening. 

 No trace of a specialized labial armature was present other than 

 the simple cuticular thickening. 



Radula. The pharyngeal bulb is a nearly spherical mass, 

 2.1 mm. in diameter, the radula sheath forming but a slight 

 prominence upon the lower, posterior surface. The radula is 

 broad, short and deeply grooved. The teeth are in 49 rows, of 

 which the first, the oldest, are more or less worn away and 

 incomplete. The rhachis is naked, the pleurae, 60 in number 

 on each side, are strongly hooked, and of a similar shape through- 

 out. The bases are moderately thick and heavy, the hooks 

 blunt and flattened (PI. XV, figs. 78, 81). The shaft and hook 

 of each tooth lie in the same plane, the tip of the hook not being 

 directed toward one side as is usually the case. The dimensions 

 of a typical tooth are: length of base 0.082 mm., height of 

 hook 0.049 mm., width of base 0.005 ^^- The outermost 

 tooth of each row is smaller than the remaining ones (PI. XV, fig. 

 79), as are also the innermost pleurae (PI. XV, fig. 80). The 



