80 Carl Bovallius, The Oxycephalids. 



Gen. 6. Streetsia, Th. Stebbing, 1888. 



The name was given by Stebbing in lionour of D:r Th. H. Streets, of the 



United States' Navy. 



Diagn. The head is very long, narrow, produced into a long, evenly 



tapering, sharp-pointed rostrum, which is open on the under 



side. The hind part of the head is more or less constricted, 



but does not form a neck. 

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



folded. 

 The first pair of perœopoda are subcheliform; the second are 



more or less cheliform. The carpus and metacarpus of the 



fifth pair are not dilated. 

 The last coalesced ural segment is not twice as long as the 



first, and more or less elongated. 

 The inner rami of all the three pairs of uropoda are free, 



not coalesced with the corresponding, peduncles. 

 The telson is triangular, sharp-pointed, and more or less 



elongated. 



Si/n. 1888. Streetsia, Th. Stebbing. 39, p. 1603. 



The original generic diagnosis of Stebbing contains some charac- 

 teristics which, in my opinion, have only specific value, as for instance 

 those respecting the last five pairs of perseopoda and the length of the 

 telson. The diagnosis runs: 



y>Head not constricted at the base, much longer than the peraeon, 

 the rostrum very elongate and the eyes still more so. 



The Gnathopods complexy subchelate. The second Perœopods longer 

 than the First. The Fourth Perœopods with the hinder apex of the first 

 joint acutely produced. The Fifth Perœopods with dilated first joint 

 exceeding in length the other five joints together; the outstretched 

 limb exceeding in length the first joint of the fourth pair. 



The Uropods with the rami distinct from the peduncles; the Third 

 Uropods with peduncles much longer than broad. 



The Ttlson produced far beyond the uropods, much longer than 

 the coalesced fifth and sixth segments of the pleon.» 



According to my views on the systematization of the Oxycephalids 

 Oxycephalus porcellus, Claus, O. longiceps, Claus, O. pronoïdes, C. 

 Bovallius, O. Steenstrupi, C. Bovallius, and a new species, here to be 



