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inner margin of the orbit. For the rest there is no difference in the course of the inner and 

 upper orbital margin between the two species, but the external orbital angle is less acute 

 in H. subquadrata^ the outer margins of these angles are somewhat diverging backvvard and 

 as long as the subparallel margins of the anterior epibranchial teeth ; the posterior teeth are 

 much smaller, more acuminate and directed obliquely-outward, so that the greatest width of 

 the carapace is found between the tips of these posterior teeth; behind the latter the side 

 margins are parallel, slightly concave. Any tracé of additional notches, which in H. tridens 

 mark off a third and even a fourth pair of epibranchial teeth on the postero-lateral margins 

 of the carapace, is altogether absent in the present species. 



The margins of the front, of the orbits and the antero-lateral borders of the carapace, 

 up to the posterior lateral teeth, are continuously granulate and the whole of the lateral 

 margins is accompanied by a ciliated row immediately beneath the margins. The side walls 

 of the body are vertical and, like the pterygostomian regions, ornamented in the usual way 

 of the Sesarminae. 



Owing to the inflated under parts of the body the epistome is vertically placed, but 

 not projecting beyond the front in dorsal view. In accordance with the presence of 

 a "musical crest" on the cheliped the in fra -orbital border is peculiarly 

 trans formed. Begin n ing from the epistome the whole orbital portion is 

 occupied by a series of about 12 obtuse verrucosities, that are finely trans- 

 versely striate; the series is interrupted in the middle. Beneath the cornea 

 of the eye and at the end of the orbital portion we observe a large, 

 rounded, elongate tubercle, that late rail)- and backward tapers into a 

 ridge of about twice the length of the tubercle itself; this ridge at the 

 end again rises into a small tubercle of similar shape as the preceding. 

 The shape of the infra-orbital border is widely different from that of H. tridens, but it 

 approaches that of H. latrcilli: in both species the infra-orbital border reaches backward only 

 to the first notch of the lateral margin of the carapace, and an elongate tubercle is found 

 beneath the cornea of the eye, but laterally and backward this tubercle or thickened ridge is 

 foliowed in H. latreilli, according to de Man's description, by 3 — 4 similar, but smaller 

 tubercles (only one in the present species) and the orbital portion is occupied either by a 

 continuous wavy crest or a series of 3 — 4 elongate, transversely-striate tubercles, foliowed by 

 5 smooth granules towards the epistome. 



The part of the sternum between the abdomen and the bases of the 

 external maxillipeds is shortly hirsute. This character has been also figured by 

 Dana in his figure 5 a and it is indeed one of the chief reasons why I referred my specimen 

 to his " Chasmagnathus" subquadratus. In II. leachi the anterior part of the sternum is also 

 hairy, but here the hairs are much larger. De Man in his discription of H. latreilli does not 

 particularly state, that the hairs of the maxillipeds extend to the sternum, but if they do, we 

 may safely assume, that it would not have escaped to de Man's experienced eye. 



In comparing my figure \d with de Man's figure \\c of H. latrcilli it at once becomes 

 obvious that the abdomina of the two species are very much alike, but in H. subquadrata 



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