422 HYALIXCECIA TUBICOLA. 



Torres Strait, and Canary Islands (< Challenger '). Japan (J. P. Moore). West Indies 

 (Augener). Bast Indies and Africa (Ehlers). 



The wide distribution of this species and its varieties is noteworthy. 

 Head (Plate L1V, fig. 5 a) agrees generally with that in 0. conchylega, the tentacles 

 arising from ringed bases, and being long and smooth. No eyes. The anterior processes 

 (frontal palpi, Pruvot, and palpi, Claparede) are somewhat pyriform and slightly 

 marked by transverse wrinkles in life, but in spirit ovate. The palpi form two bulbous 

 pads with a median furrow ventrally. 



Body typical. The first segment is narrower than the succeeding, and is smoothly 

 rounded from side to side. The mouth-parts (Plate LXV, fig. 15) present two bulbous 

 processes at each side of the aperture, with the mandibles posteriorly. 



Proboscis (Plate LXIV, fig. ha). — The maxillae have a rather short hooked region 

 anteriorly, the enlarged region extending far forward. The tips are sharp. The posterior 

 processes are bluntly conical. A dark brown border to each runs forward and joins a 

 transverse bar between them and the maxillae, and from the centre a line passes obliquely 

 outward on each side to a dark spot at the end of the great dental plate. The right 

 great dental plate has teeth throughout nearly its entire extent, but they vary in number 

 apparently according to the size and age of the specimen. In the examples from the 

 ' Challenger ' there are fourteen teeth. A British one had thirteen teeth ; the left great 

 dental plate has about thirteen. The left anterior curved plate has four, and the right 

 anterior curved plate four. The mandibles have a slightly denticulated edge anteriorly, 

 and long tapering shafts. The second segment is considerably broader and bears the 

 first feet, which are proportionally massive organs directed forward with a disk-like 

 process at the tip. The dorsal cirrus is somewhat short and stout, and arises from the 

 mid-dorsal region of the foot. The posterior papilla springs from the tip of the 

 foot behind the disk-like flap. It is subulate. The ventral cirrus, again, arises 

 near the base of the foot ventrally. The setigerous region is supported by three 

 spines, and a series of strong, bifid winged falcate bristles (Plate LXXXIV, fig. 8). 

 The tip is strongly hooked, and beneath the hook is a prominent secondary process, 

 closely resembling that in Onuphis britanniea, though the attachment of the wing is nearer 

 that process. 



The second foot is considerably shorter and only slightly inclined forward, and as a 

 consequence the cirri and papilla are nearer each other. It bears both simple bristles 

 with a winged and tapering tip, and bifid hooks. The ventral cirrus forms a stout 

 subulate process, that of the next foot (fourth), however, being shorter and its tip blunt. 

 In the following three feet it gradually diminishes into the pad at the ventral edge of the 

 foot. The lower bristles of the dorsal series in the anterior region, e.g., the eighth foot 

 (Plate LXXXIV, fig. 8 d), have shorter tips and broader wings. 



At the tenth foot (Plate LXXV, fig. 11) is dorsally the proportionally large and 

 somewhat fusiform dorsal cirrus — tapering, however, more toward the tip. The seti- 

 gerous region has dorsally one or two long and rather stout bristles, with winged and 

 tapering tips (Plate LXXXIV, fig. 8 a), besides a group of brush-shaped forms (Plate 

 LXXXIV, fig. Sb). Below is a group of similar bristles with broader wings and shorter 

 tips. The hooks do not seem to be prominent in these feet. The papilla at the posterior 



