128 CARCINOLOGICAL NOTES; 



found that its affinities are not with the Palaemonidae, but rather with 

 Atya and Caradina, as it possesses the mandibles characteristic of that 

 group. 



Genus HIPPOL YSM A TA STIMPSON. 



Hippolysmata wurdmanni Stimpson. PI. I, fig. 8. 

 Hippolysmata intermedia Kingsley. PI. I, fig. 4. 



I give figures of some details of these two species to aid in their 

 identification. 



Genus NECTOCRANGON BRANDT. 



M". alaskensis nov. 



Carapax but little depressed, with four prominent equally spaced 

 teeth in the median line, the anterior one forming the rostrum, and 

 with a fifth smaller tooth between the first and second. A strong 

 spine on each hepatic region. Front strongly elevated, the orbits 

 elongate, tubular, and each with two spiniform teeth above. Ptery- 

 gostomian spine very prominent. Peduncle of antennulse barely 

 reaching to middle of the antennal scale, and the flagella not reaching 

 its tip, otherwise both pairs of antennae are much as in N. lar. The 

 external maxilipeds and thoracic feet present no important differences 

 from N. lar. The sterna of the three last thoracic segments bear 

 large prominent spines. The abdomen has a median dorsal carina, 

 which on the sixth segment and telson is double as in the previously 

 described species. Length about one and one-half inches. 



Marmot Island, Kodiac Archipelago, Alaska (Dr. W. H. Jones, 

 Philadelphia Academy). 



Genus CRANGON FABRICIUS. 



Crangon tenuifrons not?. PI. I, fig. 10. 



Carapax depressed, its surface uneven, with two spines in the me- 

 dian line above, of which the posterior is just behind the middle and 

 the smaller, anterior one at the base of the rostrum. Rostrum 

 elevated, arcuate, somewhat elongated, and reminding one of that of 

 Sabinea septemcarinata. Subocular, pterygostomian, and hepatic 

 spines prominent. Antennulse with a broad basal scale, the peduncle 

 extending nearly to the middle of the antennal scale. Two flagella 

 present, the outer thicker one reaching the tip of the antennal scale, 



