184 STALK-EYED CRUSTACEA. 



In Aill grown specimens of 6*. agassizn, -which attain a length of 150 mm., 

 the antennnlai- flagella are only one half as long as the carapace, or even 

 less. The flagella of the second pair of antennre are very slender and enor- 

 mously long, — more than two and two thirds times the length of the whole 

 body. The nnmber of teeth on the rostrum and gastric region in full-grown 

 individuals is nine. The sharply defined cervical groove does not quite reach 

 the median dorsal line of the carapace, although the doi'sal carina is inter- 

 rupted at that point. The sides of the rostrum are tomentose, as appears to 

 be the case in S. siphonocera and 8. distinda (De H.). 



Measurements of a female (Station 3391) : length of body, 149 mm. ; 

 length of carapace, including rostrum, along median dorsal line, 54 mm. ; 

 length of rostrum, 13.5 mm. ; length of antennule, 46.5 mm. ; length of 

 antennular flagella, 28 mm.; length of antenna, 410 mm.; merus of third 

 legs, 21 nnn. ; carpus of do., 3G.5 mm. ; chela of do., 10 mm. ; antennal scale, 

 22.5 mm. ; telson, 22 mm. 



Station 3389. 210 fathoms. 2 males, 8 fem. 

 3391. 153 " 5 males, 6 fem. 



The branchial formula of Sulenoccra agassizii is as follows: 



19 + (7) 

 The pleurobranchia on the last thoracic segment is small but functional. 

 The lateral brajiche.s of each gill arc alternately arranged on each side of the 

 main stem, and are curved so that their distal ends meet the ends of their 

 fellows on the opposite side of the stem, and thus form a hollow tube which 

 is open and obliquely truncated at the distal end. There are small exopods 

 attached to all the legs. On the second maxillipeds the exopods reach to 

 the end of the merus, but they gradually decrease in length through the 

 series of following appendages. 



The geographical distribution of this interesting genus, as far as known, 

 is as follows: S. siphonocera ,-\ the type of the genus, is found in the Mediter- 



• One of these is possibly n pleurobranchia rather than an arthrobranchia. 



t Perueus memhranaceus M. Edw. (Hist. Nat, Cnist., IT. 417, 1837), nee Risso ; Tcneus siphonoceros 

 Philippi (Arch. Naturgesch., VI. Jahrg., I. 190, Plate IV. Fig. 5, 1810) ; Soleiweera philijipii Lucas (Ann. 

 Soc. Entomol. Fiance, 2« Scr., VIII. 223, Plate VII. No. II. 1850); Solenoca-a siphonocera Miers (I'roc. 

 ZoOlog. Soc. London, 1878, p. 301). 



