REPORT ON THE CRUSTACEA MACRURA. 755 



Acanthcphyra approxima, n. sp. (PI. CXXVI. fig. 8). 



Carapace dorsaJly compressed, and carinated from the posterior margin to the rostrum, 

 which is broken, slender almost from the base, and armed with seven teeth on the upper 

 surface, the four posterior of which are small and closely packed together, the other three 

 are larger, and the most anterior corresponds with the posterior on the lower margin, at 

 which point the rostrum is broken. The first somite of the pleon is slightly carinated on 

 the dorsal surface, the second is conspicuously so, the third and three followino- are 

 carinated and produced posteriorly to a well-developed tooth. 



The telson is anteriorly slightly carinated and terminates in a small brush-like 

 extremity that does not reach beyond the distal extremity of the inner branch of the 

 rhipidura. 



Habitat.— Station 310, January 10, 1876; lat. 51° 27' 30" S., long. 74° 3' 0" W.; 

 Sarmiento Channel, Patagonia ; depth, 400 fathoms ; bottom, blue mud ; bottom tempera- 

 ture, 46 0- 5. One specimen. Trawled. 



The carapace is dorsally carinated from the posterior to the frontal margin, where it 

 is produced to a rostrum that is armed on the upper surface at the base with four 

 closely compressed teeth, and with three more separated on the rostrum, and one on the 

 lower surface corresponding with the most distal on the upper, at which point the 

 rostrum is broken. 



The frontal margin beyond the second antennal tooth obliquely recedes until it 

 reaches a point defined by the branchial margin of the carapace abruptly forming a sharp 

 bend that is marked by an angle, which is posteriorly increased to a ridge that traverses 

 the carapace from the anterior to the posterior regions. On the outer side of this ridge 

 the surface lies at right angles with the rest of the carapace. 



The pleon has the lateral walls perpendicular untd they recede to the dorsal carina, 

 which commences and ends abruptly on the second somite ; it recommences on the third 

 also abruptly, but is produced posteriorly to a long tooth at the posterior margin, and this 

 is repeated in each of the following somites, the under surface of the tooth corresponding 

 closely with the outline of the next somite, so that when the animal is extended the 

 denticular character becomes a knife-like edge. 



