MALMGBEXIA OASTANBA. 381 



under surface of the body is iridescent pinkisb. In some a considerable amount of 

 brown pigment occurs posteriorly on each side of the median groove, and on the 

 segmental eminences, the site of the papilla being indicated by a darker speck. On the 

 whole the body is rather firm and broad, tapering a little anteriorly and more so 

 posteriorly. It terminates in two tapering caudal cirri, often of a deep brownish hue. 

 The segmental eminences are fairly developed, but no distinct elongation of the papillae 

 occurs. 



Scales (Plate XXXIII, fig. 10), fifteen pairs, covering the dorsum, only a brief 

 portion of the tail being uncovered. The first pair are rounded, the succeeding reniform, 

 then ovoid, while the large posterior scales are irregularly quadrate. They are smooth 

 glistening organs under a lens. Under the microscope they present a somewhat trian- 

 gular group of papillae on the anterior concavity of the reniform scales, but in the 

 posterior scales these almost disappear. They are surrounded by a madder-brown belt, 

 with a tendency to the development of a denser portion in the anterior band. In 

 addition to broader marginal belts, the posterior scales have a general sprinkling of the 

 brown pigment. In some, especially those near the mouth of Spatangus purpureas, 

 all the exposed portion of the scale is tinted of a deep madder-brown. The scales 

 seem to adhere with considerable tenacity. The nerve-supply is similar to that in 

 Scalisetosus communis, but it is considerably obscured by pigment. 



Feet. — In those examined only a spine occurred in the first foot. 



In the typical foot (Plate XXX, fig. 5) the dorsal lobe is not much developed, form- 

 ing a small process from which the somewhat short bristles project. They are very 

 slightly curved, and taper a little towards the tip, which ends in a short point (Plate 

 XL, fig. 23). They are translucent, finely striated longitudinally, and with faint spinous 

 rows which go almost to the point. The dorsal spine projects in its sheath only a short 

 distance towards the lower edge of the bristle-bundle. The ventral bristles have slender 

 translucent shafts with a median axis, and striae distally as well as in the spinous region. 

 The ordinary appearance of one of the superior ventral bristles is shown in Plate XL, 

 fig. 24, scarcely a trace of the secondary process being visible below the well-marked 

 hook at the tip, and it altogether disappears ventrally (Plate XL, fig. 25). In the 

 developing form the secondary process is clearly indicated. The spinous rows are 

 close, and leave only the short terminal region bare. In specimens from Yalencia (south- 

 west of Ireland) this process is very distinctly seen, for instance, when the bristle is 

 slightly turned round (Plate XL, fig. 26). The secondary process is less marked in 

 specimens from the Channel Islands and Shetland, though indications are present in all. 

 In viewing the body from the ventral aspect the feet after the thirteenth become con- 

 siderably larger, and continue so till the thirtieth. This, as in Harmothoe marphysde, 

 may be associated with reproduction. 



The dorsal cirri are of moderate length, smooth, slightly enlarged towards the end 

 of the column (in spirit), and with a filiform tip. They increase in length (as usual) 

 posteriorly. The ventral cirri extend to the bases of the bristles, and are subulate and 

 smooth. 



In a small example dredged at 480 fathoms off the south-west coast of Ireland 

 both dorsal and ventral bristles are shorter and proportionally thicker, the former being 



