72 Carl Bovalliub, The Oxycephalids. 



length, and serrated; the inner ramus is broader than the outer. The 

 third pair reach fully to the apex of the teleon ; the peduncle is half 

 as long as the inner ramus, which is more than twice as broad as, and 

 a little longer than, the outer. 



The telson is triangular, with curved margins, and is a little 

 longer than it is broad at the base. 



Colour. Brownish, with dark red spots. 



Length. 9 — 13 mm. 



Hab. The Indian Ocean. 



Gen. 4. Calaniorhyiiclius, Th. Streets, 1878. 



Diagn. The head is long and broad, produced into a long, broadly- 

 dilated and sharp-pointed rostrum, which is open on the under 

 side. The hind part of the head is constricted, forming a 

 short neck. 



The second pair of antennœ are hidden under the head, when 

 folded (?). 



The first two pairs oî iierœoi)oda are subcheliform. The carpus 

 and metacarpus of the fifth pair are not dilated. 



The last coalesced ural segment is nearly three times as long 

 as the first, and nearly four times as long as it is broad. 



The inner ramus of the third pair of uropoda is coalesced 

 with the corresponding peduncle. 



The telson is elongated, and narrowly triangular. 



Syn. 1878. Calaniorhyuchus, Th. Streets. 26, p. 285. 



» » Th. Stebbing. 1888. 39, p. 1599. 



This genus is at the first view easily distinguished from all the 

 other genera by the peculiar form of the head, with its wing-like 

 expansions of the rostrum; in this characteristic TidlbergeUa comes 

 nearest to it, but is very different from it in almost all other 

 points. 



Beside the typical species, Calamorhynchus pellucidus, de- 

 scribed in 1878 by Streets, another, C. rigidus, is given by Stebbing 



