SOLENOCERA AGASSIZII. 183 



The branchial formula is as follows : — 



18 + (G) 



The gill on the eighth somite entered as a pleurobranchia in the above 

 table has been considered an arthrobranchia by some recent authors, but 

 from its relative position it would seem to be the equivalent of the pleuro- 

 branchite of the following somites. The epipods consist of a horizontal stem 

 directed backward from the basal segment of the limb, and a vertical forked 

 blade which lies between the gills. 



Length, 93 mm. ; carapace, exclusive of the rostrum, 29.5 mm. 



Station 3371. 770 ftithom.s. 1 male. 



SOLENOCERA Lucas. 

 Ann. de la Soc. Eutomol. de rrance, 2d Ser., VIII. 219, 1850. 



Solenocera agassizii Fax. 

 Plate XL VII., Fig. 2-^. 



Bull. Mus. Coiiip. Zool., XXIV. 211, 1S93. 



Closely related to S. dphonoccra (Philippi), but differing from the latter 

 in having the antennular flagella much shorter and subequal, and more 

 teeth on the upper margin of the rostrum and gastric region. Comparison of 

 a specimen with one of S. siphonocera of equal size (57 mm. long) from the 

 Bay of Naples shows that in S. agassizii the antennular flagella are only 

 four fifths the length of the carapace, and that there are eight teeth on the 

 rostrum and gastric region, while in S. siphonocera the antennular flagella 

 are as long as the distance from the tip of the rostrum to the middle of 

 tlie third abdominal segment, — or once and two fifths the length of the 

 carapace, — and there are but six teeth on the rostrum and gastric region. 

 Moreover, not only is the upper flagellum broader (1 mm.) and blunter in 

 ;S'. agassizii than it it is in S. siphonocera (where it is only \ mm. in breadth), 

 but also subequal in breadth to the lower flagellum, whereas in the Mediter- 

 ranean species the upper flagellum is conspicuously narrower than the lower 

 one. 



