Boone, Cmstacea, Cruise of "Alva" 1931 59 



and one-half times as wide anteriorly as long and slightly more 

 than twice as wide anteriorly as posteriorly, with the frontal mar- 

 gin slightly arcuate, the orbit anterolateral in position, the true 

 preorbital angle a solitary acute tooth directed laterally; the 

 supraorbital border is a conspicuously upcurved bifid tooth an- 

 teriorly from which there runs backward a carinate beaded ridge, 

 interrupted by a second tooth, which is also carinate posteriorly 

 to a point opposite the base of the posterior tooth of the lateral 

 margin. The postorbital tooth is acute, stout, and inside of it there 

 is a smaller denticle or blunted low tooth on the outer half of the 

 orbital margin. There is a strong acute tooth on the lateral 

 margin, which is about opposite the termination of the ridge 

 and also opposite the anterior end of the oblique median lateral 

 beaded line which extends from this point obliquely outward and 

 terminates on the posterior margin of the carapace. This line is 

 composed of solitary, rounded, pearly granules, similar to those 

 found along the frontal and lateral margins. The median dorsal 

 line of the carapace and first six abdominal segments is elevated 

 into a prominent ridge, v/hich on the carapace consists of three 

 acute upward pointing teeth, the most anterior rostral one being 

 the smallest, situated just behind, but overhanging the frontal 

 margin and with the carina behind the tooth not pronounced ; the 

 second or gastric tooth, which is approximately opposite the lat- 

 eral tooth, is larger and more elevated than the first tooth and has 

 its posterior carina more pronounced; the third tooth, which is 

 slightly posterior to the middle of the carapace and is postcervical 

 or epicardiac, represents the apex of height of this median crest 

 and is continued posteriorly as a beaded ridge, interrupted by a 

 double low tubercle, suggestive of a rudimentary tooth, situated on 

 the intestinal area just anterior to the posterior margin of cara- 

 pace. The cervical groove is shallowly but distinctly delineated, 

 curving outward and terminating anterior to the hepatic tooth. 

 In addition to the above described lines of large, low, rounded tu- 

 bercles, there are scattered over the entire dorsal surface of the 

 carapace numerous, solitary, low, flattish, circular squamae which 

 stand out in bas-relief among the furry coating, which is composed 

 of fine, short pilosity forward-directed and more abundant and 

 longer on the frontal and orbital margins and hepatic regions. 

 The median rostral process is small. The true rostral process is 

 composed of a small, acute median point or tooth, semiconcealed 



