40 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL, 1 28 



Canada. This species measures from 7 to 10 mm., and occurs from 

 shallow water down to 300 m. 



Family PLEUSTIDAE 

 PLEUSTES PANOPLA (Kroyer) 



Figure 14, o 



Amphithoe panopla Kroyer, 1838, p. 270, pi. 2, fig. 9. 



Aniphithonotus cataphractus Stimpson, 1854, p. 52. 



Pleustes panoplus Hansen, 1887a, p. 119.— Sars, 1893, p. 344, pi. 121.— Ort- 

 MANN, 1901, p. 150.— Holmes, 1905, p. 488, text fig. ; pi. 7, fig. 3.— Stebbing, 

 1906, p. 310. — Shoemaker, 1930b, p. 309. — Stephensen, 1938, p. 253, fig. 28; 

 1944a, p. 4; 1944b, p. 48. 



Material collected. — In 80 feet, September 9, 1948, i specimen. In 

 37 feet, 0.75 mile out, in screen trap through hole in ice, March 10, 

 1950, I specimen. From beach at Point Barrow base, September 28, 

 1950, I specimen. 



Pleustes panopla is a circumpolar species that dips down into the 

 cold waters of the North Atlantic and North Pacific. There are 

 specimens of this species in the U, S. National Museum from Lab- 

 rador, Gulf of St. Lawrence, Bay of Fundy and south of Marthas 

 Vineyard {Fish Hawk station 987, 40° 54' N., 70° 48' 30" W.) ; and 

 in the Pacific from Bering Sea and off Japan (Albatross station 4828, 

 37° 23' N., 137° 36' E.). It was recorded from the Sea of Japan 

 in 1930 by A. N. Derjavin. 



William Stimpson in 1854 described Amphithonotus cataphractus 

 from Grand Manan, Bay of Fundy, but gave no figures. His descrip- 

 tion applies very well to Pleustes panopla (Kroyer), which occurs at 

 Grand Manan. I have examined many specimens of P. panopla from 

 New England, Gulf of St. Lawrence, Bay of Fundy, and Labrador, 

 and they all agree in all characters with a typical specimen from Grand 

 Manan, the second gnathopod of which is here figured. The palm of 

 this gnathopod is evenly convex, the proximal end passing into the 

 three rounding lobes, which form a protruding angle with the palm, 

 and each of which bears on its inside surface a group of spines ; the 

 seventh joint fits the convex palm and reaches the first group of 

 spines. Stebbing considered the three spinose lobes to be a part of 

 the palm, but believed that Sars regarded them as a part of the hind 

 margin of the sixth joint. Sars was undoubtedly correct. The first 

 gnathopod is like the second, but is not so stout and the characters are 

 less pronounced. The specimens from Alaska, Bering Sea, and Japan 

 agree with those from Grand Manan. Cecchini (Mem. 142, R. Comi- 

 tato Talassografico Italiano, p. 8, pi. 2, fig. 5) figured the second 



