504 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



Measurements in millimeters. 



Sex 



Lenjcth from tip of rostrum to tip of telson . . . 



Length of carapax, includiug rostium 



Length of rostrum 



Length of carnpax, excluding rostrum 



Height of carapax 



Breadth of carapax at branchiostcgial spines 



Greatest breadth of carapax 



Length of ej'e-stalk and eye 



Greatest diameter of eye 



Length of anteunal scale 



Breadth of ant onnal scale 



Length of second guathopod 



Length of first peraeopod 



Length of chela 



Breadth of chela 



Length of dactylus 



Length of second pera'opod 



Length of chela 



Breadth of chela 



Length of dactylus 



Length of third perteopod 



Length of propodus 



Length of dactylus 



Length of fourth per;copod 



Length of propodus 



Length of dactylus 



Length of fifth peneopod 



Length of propodus 



Length of dactylus 



Height of third somite of pleou 



Length of its dorsal sjiine 



Length of sixth somiti* of pleon 



Height of sixth somite of pleon 



Length of telson 



Length of inner lamella of uropod 



Breadth of inner lamtlla of uropod 



Length of outer lamella of uropod 



Breadth of outer lamella of uropod 



Station 2224, September 8, 1884, north latitude 30° 16' 30", west 

 longitude 68"^ 21', 2,574 fathoms, globigerina ooze, temperature 300.8, 

 two males and two females (8584). 



Acanthephyra bi evirostris, s)). iiov. 



This species is at once distinguished from the others of the genus by 

 the very short rostrum (which, though considerably longer, strikingly 

 recalls that of llymenodora glacialis), and the very large, laterally com- 

 pressed, and carinate tooth of the third somite of the pleon. All the 

 specimens are in bad -condition, very largely due, apparently, to the 

 soft and membranaceous character of the integument, which resembles 

 that o( Meningodora inoUi.s and several other deep-water species. 



The carapax i»roi>er is higher and more compressed at the base of the 

 rostrum than in A.Agassizii and the branchiostcgial spines are less prom- 

 inent. The rostrum is approximately a fourth as long as the rest of the 

 carapax, very high at base as in A. eximea^ acutely triangular in a side 

 view, terminates in a slender and slightly upturned tip, and is unarmed 

 below but armed above, at base aiKl back ui)on the carina of the cara- 

 pax, with a series of live or six very small and obscure teeth. 



The eye-stalks are a little shorter than in A. Agassizn and the eyes a 

 little smaller, but broader than the stalks, somewhat compressed verti- 



