“Rhynchothorax australis
(Plate VIII., fig. 3)
Specific characters: --
Body very robust, with lateral processes quite close together, and with median tubercles on the segments.
Chelifori absent.
Palps 5-jointed, the second joint with a very strongly developed spur dorsally.
Ovigers 10-jointed, with a terminal claw, the last four joints with a couple spines on an enlarged base.
Legs short, terminal claw with two small auxiliaries.
Body very robust, with the lateral process short and quite close together, widest across the first lateral process, and about half the breadth across the last.
The posterior articulation of the trunk is deficient, but immediately in front of where it should be, as on the preceding segments, is a stout median tubercle, bluntly pointed, and very slightly inclined forwards.
The Cephalon is expanded, but very short. The Ocular tubercle, which is stout, projects forwards and upwards over the base of the proboscis. It bears four well-developed eyes, the posterior pair being a little the larger, and terminates above them in a short cone. Measured from the anterior margin of the ocular tubercle, the cephalon is half the length of the first segment of the trunk.
The Abdomen is long, about as long as the two combined segments form which it originates.
Proboscis is stout, conical, a little longer than the first trunk segment. A conspicuous slit marks the mouth as the animal lies in its normal position.
Chelifori, no trace.
Palps. These appendages only comprise five joints, and are very curiously modified (fig. 3a). Each rises at the side of the proboscis and extends but little beyond it. The first joint is short and stout, the second is the longest of the appendage; its dorsal extremity is prolonged forwards and upwards as a stout spur. The third joint is about half as long as the shaft of the second, it is enlarged distally, a stout dorsal tubercle bearing a tuft of setae; a few other setae are more scattered. The fourth joint is small and setose, while the fifth, which is also richly setose, is reduced to a mere button.
The Oviger is very slender, ten-jointed, and rises ventro-laterally at the neck (fig. 3a). The first three joints are short, and progressively lengthen, but only to a slight degree. The fourth is nearly as long as the three together. The fifth is shorter, but swollen distally. The sixth is shorter still. No setae are discernible on any of these joints. Of the four terminals the first three are sub-equal in length, but their dorsal surfaces become more and more curved. Ventrally, also, there are prominent projections which bear the denticulate spines. The terminal joint is very broad, and a little longer than the others; its dorsal outline is very much curved, a ventrally a large swelling occupies almost the whole surface; one small spine is all that is visible. A prominent claw terminates the appendage. The denticulate spines are few in number, two on each of the first three joints. They are worn and all that remains is a slender shaft of uniform diameter with three terminal teeth, of which the middle one is the largest.
The Legs are short. The three coxae are short and stout, the second is by a very little the longest, but the first has nearly twice its diameter; it also bears a tubercle smaller than, but similar to, those borne on the middle line of the trunk. The femur is stout, and not so long as the three coxae together, but the remainder of the appendage is much more slender. The proportions of the two tibiae are as 3 to 2, the tarsus and propodus together being as long as the second tibia. The tarsus is a very small joint, its ventral surface being covered with minute spinous setae. The propodus, which is curved, has a row of them along its ventral margin, separated by rather wide intervals; several setae are scattered dorsally. The terminal claw is stout and is accompanied by two slender auxiliaries about one-third its size. A few setae are scattered on other parts of the appendage, but they do not form a prominent feature.
The Genital apertures are distinct on the second coxae of the last pair of legs only, and this joint is much swollen in consequence.
This species, of which there is only a single specimen, was found by Mr. Kirkpatrick on a sponge. Winter Quarters, at a depth of 178 fm. 7 Aug., 1902.” (Hodgson 1907, p. 57-58)
