Boone, Crustacea, Cruise of ''Alva," 1931 151 



suboval lobules of the frontal region. The orbital margin is entirely 

 closed, the superior inner orbital margin being deflected and touching 

 the tooth of the inferior orbital angle. The entire dorsal orbital mar- 

 gin is circumscribed and thickened and the inner dorsal half being 

 wider than the outer ; a slightly thicker node occurs as the postorbital 

 tooth; the anterolateral margin is widely rounded and cut into five 

 teeth besides the postorbital. These teeth incise the margin only 

 slightly but jut upward dorsally as blunted apices; the first, second 

 and third teeth each have a secondary conical elevation immediately 

 inside of the apex; the fourth tooth lacks this and is smaller and the 

 fifth tooth is quite rudimentary. There is a short sulcus running in- 

 ward on the anterior side of each tooth. The first sulcus is the one 

 that circumscribes the orbit; the second and third sulci are short 

 and confluent immediately behind the teeth ; the fourth sulcus is much 

 longer, extending across the branchial region and uniting with the 

 cervical groove; anteriorly it, together with the above mentioned 

 sulci circumscribe a small, suboval lobe the summit of which is bifid. 

 A thickened ridge occurs immediately behind the sulcus and parallel 

 to it. The sulcus from the fifth tooth is fainter yet distinct, and it and 

 the fourth sulcus circumscribe a large, sublunate flattish area on the 

 anterior of the branchial region. The gastric region is divided into 

 two low lobes by the groove that runs backward between the sub- 

 median frontal tooth ; posteriorly this groove bifurcates with a shallow 

 longitudinal ridge between the bifurcation. The urogastric groove is 

 faintly delineated, otherwise the posterior region of the carapace is 

 smooth, except for a faint carina along the short posterior margin. 

 The entire carapace and legs have a roughened pitted texture. The 

 male belt is composed of five articles, the third, fourth and fifth seg- 

 ments being fused but with the segment lines clearly delineated. 



The eye is small, entirely hooded, the stalk short and thick, with 

 a rounded, calcareous process extending a large portion of the ter- 

 minal hemispherical cornea. 



The antennulae are not very large and fold transversely within 

 the fossett which lies beneath the frontal margin and has a very thick 

 border with a thick interantennulary septum. 



The antennae have the basal article oblong, apparently fused to 

 the adjacent epistome and above to the lower margin of the outer 

 frontal tooth ; the second and third articles and flagellum are abortive, 

 situated in the notch between the outer frontal tooth and orbital angle 

 and not extending into the orbital hiatus, which is entirely closed by 

 the meeting orbital angles. 



