140 U.S. NATIONAL MUSEUM BULLETIN 2 60 



Pleustidae 



Mesopleustes Stebbing 



Mesopleustes abyssorunt (Stebbing) 



Figure 68 



Pleustes abyssorum Stebbing, 1888, p. 872, pi. 67. 



Mesopleustes abyssorum. — Stebbing, 190G, p. 315. — Cbevreux, 1927, pp. 92-93. — 



Pirlot, 1933, pp. 155-156.— Scbellenberg, 1955, p. 194.— J. L. Barnard, 1964d, 



p. 321, figs. 4, 5. 



A few characters of quantitative extent differentiate this specimen 

 from those previously described. The dorsal carina is more pro- 

 nounced on the anterior pereonites than in specimens from Marion 

 Island and Japan described by Stebbing (1888) and J. L, Barnard 

 (1964d) but the processes of pleonites 1-3 are blunter. The lateral 

 cephalic lobe is sharper than that from Japan and the pereopodal 

 dactyls are longer than any heretofore described. The rostrum is 

 slightly curved like that of the specimen from Marion Island but not 



Figure 68. — Mesopleustes abyssorum (Stebbing), male, 22.0 mm, Baja Slope Expedition 

 Sta. P 285-61: a, accessory flagellum marked with arrow on antenna 1; h, pereopod 4, 

 medial; c, dorsal outline of body, left side, pereonites 1-7 and pleonites 1-6 marked; 

 d, head and bases of antennae; e, lower lip;/, coxa 1. 



