REPORT ON THE CRUSTACEA MACRTJRA. 709 



The first pair of antennae (fig. lb) has the peduncle subequal in length with the 

 rostrum, against the under side of which it lies ; the first joint is broad and carries an 

 obtusely-pointed, squamous stylocerite on the outer side ; the other two joints are 

 cylindrical and support at the extremity two flagella, one stout and the other slender, 

 the former being bifurcated at the extremity into two short rami ; neither is more than 

 half the length of the peduncle. 



The second pair of antennae (fig. lc) lies on the outer side of the first and is enclosed 

 within a fold of the carapace formed by the lateral margin being bent acutely under 

 it, the frontal angle, extending forwards beyond the articulation of the scaphocerite, is 

 thickened to a strong ridge that precludes its downward movement. The scaphocerite 

 is short and discdike, being nearly as broad as long, and has the outer margin distally 

 armed with a short point or tooth. 



The mandible (fig. id) is divided into a molar process and a pointed psalistoma, 

 but possesses no synaphipod. 



The first pair of siagnopoda (fig. le) is three-branched ; the two inner branches are 

 broad, flat, and disc-like, and have the inner margin thickly matted with short, stiff 

 hairs ; the third or outer branch is short, cylindrical, and truncate. The second pair 

 (fig. If) is likewise three-branched ; the inner branch is long, narrow, pointed, and has 

 the inner margin thickly fringed with long hairs ; the middle branch is short, narrow, 

 cylindrical, and smooth ; the outer or third forms a large mastigobranchial plate that 

 projects anteriorly beyond the extremity of the other two branches and posteriorly 

 into a rounded margin ; it is fringed anteriorly and posteriorly with hairs ; those on the 

 rounded posterior portion tending to curve anteriorly ; the longest hairs are at the 

 posterior extremity, the next longest at the anterior, and the shortest, which are almost 

 obsolete, at the broadest diameter of the plate. 



The third pair of siagnopoda (fig. Ig) consists of four branches or divisions ; the 

 inner branch is broad and long and has the inner margin fringed with an even 

 row of short hairs ; the middle branch is short, narrow, cylindrical and smooth ; and 

 the outer is broad at the base and smooth at the margins, and from its inner margin 

 near the apex there arises a long, narrow, compressed, ribbon-like process that is 

 distally tipped with short hairs, and on the outer surface near the base is a small 

 bilobed mastigobranchia. 



The first pair of gnathopoda (fig. lh) is six -jointed; the coxa is short, robust, and 

 supports a broad, short, and square-shaped mastigobranchia ; the basis is long, has the 

 inner and outer margins parallel, and carries a two-jointed ecphysis, of which the first 

 joint is the more robust ; the third joint or ischium is short and subcylindrical, as is also 

 the meros, which anteriorly projects beyond the base of the next joint, and represents 

 the meros and carpos combined ; the terminal two joints are reflexed against the inner 

 margin of the meros and together form a semdunar disc-like plate, the clactylos forming 



