GLYCEBA SIPHONOSTOMA. 485 



The twentieth foot has two long conical papillae anteriorly, and two flattened 

 truncated lobes posteriorly, besides the dorsal cirrus and the shorter ventral cirrus.. 



The dorsal bristles (Plate LXXXV, fig. 4) are translucent, simple, with a slight 

 forward curvature of the shaft below the tip which inclines a little backward and then 

 forward at the finely tapered extremity. The edges of the tip present traces of wings. 



The ventral bristles (Plate LXXXV, figs. 4 a and 4 b) have somewhat stouter shafts, 

 also with a slight bend forward and then backward toward the dilated end, below which 

 a slight constriction occurs. The dilated end of the shaft is split for articulation with the 

 thickened base of the terminal blade, which then is flattened and gradually tapered to a 

 fine point. 



Both dorsal and ventral bristles extend beyond the anterior conical lobes. 



The two anterior lobes have increased in size at the thirtieth foot (Plate LXXVI, 

 fig. 2 a), and the bristles are proportionally longer. The ventral lobe is somewhat less. 

 Little change occurs from the foregoing to the ninetieth foot, and indeed to the posterior 

 end of the fragmentary examples. The bristles are arranged in two bundles in each 

 division of the foot. The foot is therefore characterized by the two pointed anterior and 

 the two blunt posterior lobes. 



A typical foot, e.g., the thirtieth, is comparatively short, and the dorsal cirrus is 

 more closely connected with it than in some forms, so that in profile it is distinctly a part 

 of the outline of the foot. The two anterior lobes are broadly lanceolate with pointed 

 tips and are about the same length. The ventral lobe does not extend so far outward, 

 but, as it arises near the base of the foot, it is of considerable length, and the tip is also 

 pointed. The two posterior lobes form short blunt flaps. The characters of the foot 

 remain more or less distinct to the posterior end, as, for instance, in the twentieth from 

 the tip of the tail (Plate LXXVI, fig. 2 b). 



In some forms, e.g., that dredged by the ' Porcupine ' off Cape Guardia, in 1870, the 

 two anterior lobes are considerably elongated (Plate LXXVI, fig. 2 c). 



The posterior portion of the body is readily reproduced, a provision which renders 

 the frequent ruptures during its violent muscular exertions less serious (Plate LXIV, 

 fig. 8 a). 



Reproduction. — At Naples Lo Bianco 1 found this form mature from December to 

 April. 



Habits. — They are active animals, progressing through the water with a wriggling 

 screw-motion — probably as they do through wet sand. When irritated the proboscis is 

 ejected, and the organ is used to perforate the sand. They apply the pointed snout to 

 the surface, and then by a vigorous thrust of the proboscis a considerable space is 

 penetrated. They seem to be liable to wounds and ruptures, and are irritable. 



In the cavity (stomach) behind the proboscis in one from the south west of Ireland 

 was a considerable portion of a Gapitella, so that like many other Annelids the species is 

 carnivorous. 



The early description of Delle Chiaje (1825) with the accompanying figures is 



recognizable, especially by aid of the subsequent observations of Claparede and a specimen 



kindly sent by E. Grrube. Delle Chiaje records the actions of the proboscis on immersing 



the animal in spirit. 



1 ' Mitth. Zool. Stat. Neap./ xiii, p. 491. 



