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The body of So/. Melatitho is smooth, glabrous. The carapace, rostrum included and 

 measured near the dorsal line, is long one-third the total length; the carapace is distinctly 

 compressed, its height being in proportion to its transverse diameter as 5:4. Abdomen twice 

 or little more than twice as long as the carapace. The rostrum is short, reaches to the tip 

 of the eye-peduncles, often hardly as far, and measures in adult specimens one-third the rest 

 of the carapace, while in younger individuals it appears comparatively a little longer; its form 

 is rather stout, the height near the base (the teeth included) being one-third its length or 

 sometimes even more. The slightly ascending, upper margin is armed with 8 or 9 strong teeth 

 that reach to the tip ; sometimes the foremost tooth is as far distant from the tip as from the 

 penultimate tooth, sometimes twice as far, and in other specimens it is farther distant from the 

 penultimate tooth as from the tip. The three first teeth are situated on the carapace, the 4"* 

 just above the orbital margin; the i'' tooth is one and a half as far distant from the 2"'' as 

 the 2"<^ from the 3'"^ and the distances between the following teeth slightly become shorter 

 distally. Post-rostral carina not interrupted by the cervical groove, very prominent and reaching 

 to near the posterior margin of the carapace. The lower margin of the rostrum, more ascending 

 than the upper, appears very slightly concave in the middle ; it is unarmed and fringed with 

 long hairs. The lateral sides of the rostrum are tomentose above the lateral ridge, that is hardly 

 traceable to the acute tip, as it fades away just below the foremost tooth. 



Orbital angle more or less dentiform and sharp. Post-antennular (antennal) spine small ; 

 between this spine and the orbital angle another somewhat larger, the post-orbital spine, at 

 some distance from the anterior margin of the carapace and situated nearer to the orbital angle 

 than to the antennal spine; neither of them are produced backward as a carina. There is a 

 small impression midway between the post-orbital spine and the rostrum. Hepatic spine small, 

 of the same size as the antennal spine, situated much lower, in a horizontal line with the upper 

 margin of the basal joint of the outer antennae. Cervical groove deeply cut, reaching upward 

 to near the post-rostral crest, which it therefore does not indent; the upper e.xtremity 

 of the groove is situated immediately before the middle of the carapace. A narrow, but rather 

 deep, transverse groove runs from just behind and below the post-orbital spine downward, 

 meeting the cervical groove just in front of the hepatic spine; the subhepatic groove, i.e. the 

 antero-inferior part of the cervical groove, is interrupted at some distance from the antero- 

 inferior angle of the carapace and this angle is obtuse, with no spine. Between this angle 

 and the interruption one observes a deep, circular concavity or pit as the continuation of the 

 subhepatic groove. The anterior portion of the branchiostegal groove, below the hepatic spine, is 

 deep and runs slightly upward, the posterior portion between the cardiac and branchial regions 

 is also visible, though broader and shallow, but the middle part is inconspicuous. Besides the 

 dentiform, orbital angle there are three spines on the side of the carapace. 



Abdominal terga carinate from the i^^ to the 6'^, except the anterior third part of the 

 3"! and the carina of the 6"^ terminates alone in a tooth. Si.\th somite little longer than the 

 5"> and one-fourth longer than high: in the adult female, long 132 mm., from Stat. 302, the 

 5''^ tergum is 13 mm. long, the 6"' 14 mm. long and ii mm. high; in the adult male from 

 Stat. 312 these numbers are, in the same succession, 9,75 mm., 11,4 mm. and 7,5 mm., the 



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SIBOGA-E.'CPEDITIE XXXIXO. 7 



