REPORT ON THE PYCNOGONIDA. 



59 



affinity with any of the other forms of Ascorhynchus described. Judging from the shape 

 of the proboscis, it comes nearest to some of the species of Colossendeis. Yet in that 

 genus the mandibles in the full-grown' animal have totally disappeared, whereas Ascor- 

 hynchus orihorhynchus in all probability has these appendages in the adult state. I 

 do not believe, however, as I have said before, that this diifereuce is in reality very 

 important, especially since I have observed among the specimens of Colossendeis gracilis 

 one furnished with long three-jointed mandibles, while these appendages were totally 

 wanting in the other specimens of the same species. 



Oorhynchus, n. gen. 



Diagnosis. — Proboscis ovate, inserted ventrally on the cephalothorax at a con- 

 siderable distance from the front margin. Mandibles rudimentary ; palpi nine-jointed. 

 Ovigerous legs ten-jointed, the four last joints not furnished with one or more rows of 

 denticulate spines. 



Oorhynchus auchlandice, n. sp. (PI. VII. figs. 1-7). 



Diagnosis. — Oculiferous tubercle horizontally directed forwards. Mandibles repre- 

 sented by single-jointed club-shaped bodies. First tarsal joint of the legs extremely small, 

 auxiliary claws wanting. Abdomen very long, once and a half as long as the proboscis. 



Description. — 



This very curiously-shaped Pycnogonid has the cephalothoracic segment short but 

 very broad, furnished at the front with. a long cylindrical oculiferous tubercle which 

 projects horizontally beyond the extremity of the proboscis. The oculiferous tubercle is 

 furnished with four eyes, two placed dorsally, and two ventrally ; the latter two are 

 the smaller. The cephalothorax is armed at the two corners with curiously-shaped spines 

 also projecting forwards, and above the attachment of the first pair of legs bears a couple 

 of long hairs placed on small knobs. Similar pairs of hairs or thin spines are also 

 observed on the two following thoracic segments on the dorsal surface between the lateral 

 processes for the insertion of the legs. The rest of the surface of the body is entirely 

 smooth. The three thoracic segments are small, and the lateral processes are separated 

 by small intervals. The abdomen, on the contrary, is very long, being once and a half 

 as long as the proboscis. The abdomen shows on both sides a row of comparatively long 

 and projecting haii-s. 



