52 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.xxxi. 



keel continuous. Rostrum and dorsal spine comparatively long. 

 Supraocular spine well developed. Antennal spine very small, almost 

 obsolete. Branchiostegal lobe rounded or angular, but without spine. 

 No postero-inferior spines. Marginal rim following closely the mar- 

 gin and leaving no laminar expansion at the postero-inferior corner. 

 Carapace not constricted in anterior part. 



Antennal scale of the type of the second group and very similar to 

 that of the young G. zoea; it is large, and the spine on the outer mar- 

 gin is slightly longer than the laminar portion. The outer edge with 

 very minute serrations in }^oung specimens, smooth in older ones. 



Abdomen of the type of the second group, at least in the young, but 

 the five anterior segments without median keel, although with short, 

 flattened, spiniform projections at posterior dorsal margin. In older 

 individuals these dorsal projections are wanting. Epimera of all 

 abdominal segments similar to those of G. zoea. 



The young specimen at hand differs from Sars's original description 

 in the following particulars: 



1. The carapace completely covers the trunk. 



2. The rostrum and the postero-dorsal spine are longer. 



3. Branchiostegal lobe not rounded, but angular. 



4. Five anterior abdominal segments with flattened median posterior 

 projection. 



5. Spine of antennal scale finely serrated on outer margin. 



The first, second, and fifth characters are of no consequence, since 

 similar variations are found in other species, and are* plainly due to 

 state of preservation o»r to age. Our specimen is young, 48 mm. long, 

 while Sars's was 56 mm. 



The angular (triangular) shape of the branchiostegal lobe (third 

 character) differs markedly from what is seen in Sars's species, and 

 the presence of flattened spines on the posterior margins of the abdom- 

 inal segments (fourth character) might also be of importance. Since 

 the present specimen is only the second individual of this species ever 

 reported, I am not prepared to say whether these two characters are 

 of specific or varietal value, or whether they simply constitute addi- 

 tional variations of age. Further material is necessary to decide this 

 question. 



Locality. — U. S. Bureau of Fisheries steamer Albatross Station No. 

 3697, 1 young; off Honshu Island, Japan; 265 to 120 fathoms. 



Previous record. — South of Fiji Islands, 610 fathoms (Sars). 



