ORDER STOMAPODA — MYSIS. 31 
ORDER If, STOMAPODA. 
Shield divided into two parts, the anterior supporting the pedunculated eyes and the antennae. 
Gills not lodged in thoracic cavities, but exposed and adhering to five pair of appendages, 
sometimes rudimentary or obsolete. The jaw-feet, and most of the feet, which are more 
than ten in number, approximating to the mouth on two lines converging behind, and 
giving rise to the name of the order. 
Oss. This order comprises few species, but which differ widely in form. Only a few of 
these species have been yet observed on our coast. 
GENUS MYSIS. Latreiille. 
Body compressed laterally. Six to eight pair of thoracic feet, and furnished with greatly 
developed palpi, which make them appear double. Mouth placed near the base of the 
antenne. No thoracic branchie ; the false abdominal feet very small, and without branchial 
appendages. 
Oss. The animals of this genus occur in immense multitudes, especially in the northern 
polar seas. According to Fabricius, they form the principal food of the Whale. 
Mysis_ sprinuLosus. 
PLATE VII. FIG. 20. 
Mysis spinulosus. M. Enwarns, Hist. Nat. des Crustacés, Vol. 2, p. 457. 
M. id Gou.p, Invertebrata of Mass. p. 333, 
Description. Rostrum depressed, triangular, and about one-third of the length of the ocu- 
lar peduncles. Peduncle of the internal antenne thick and very short ; the lamellar appendix 
of the outer antenne narrow, and ciliated only within and at the end. Medial caudal plate 
with spines on its sides, and deeply notched at the end ; the internal plates of the lateral ap- 
pendices become gradually narrowed towards the end ; the external plates very obtuse (See 
Desmarest, pl. 40, fig. 6, .). 
Color, brownish ; each abdominal ring marked above by a black star. 
