48 THE VOYAGK OF H.M.S. CHALLENGEE. 



the several other parts show any essential difFereiice from what is observed in that 

 species. 



Habitat. — All the specimens of this species were collected in the same locality, viz., oft" 

 Samboangan, Mindanao (Philippine Islands). 



Station 200, October 23, 1874; lat. 6° 47' N. ; long. 122° 28' E.; depth, 250 fathoms; 

 green mnd. 



Section 3. — Infero-posterior corners of carapace produced into two spines. Dorsal spine 

 distinctly projecting. Dorsal keel interrupted anterioi'ly. Supra-orbital spines small. 

 Antennal scale jointed at i\\)ex, outer edge jutting out anteriorly into a strong spine. 

 Maxillipeds with distinctly developed exopodites. Epimcral plates of last segment not 

 united on the venti-al face. 



11. Gnathoi^hausia gracilis, Willemoes-Suhm (PL VII. figs. G-10). 



Gnathoplumsia (jraci/is, Suliui, Trans. Linn. Soc. Loud. (Zool.), ser. 2. vul. i. ]>. 33, [.)!. ix. 



fig. 1, 1875. 

 GiiathojJnuisia grafJIis, G. (>. Sars, Preliminary Notices on the Challenger Schizopoda, Xo. IL 



Specijic Chco-acters. — Form of body very slender. Carapace not very large; dorsal 

 spine short, but distinctly projecting; infero-posterior corners armed with two unequal 

 spines, the upper one being the stronger, and about equalling in length the dorsal spine. 

 Upper lateral keel wanting. Dorsal keel armed in its posterior part with coarse, 

 anteriorly curved denticles. Cervical sulcus distinctly defined. Rostrum elongate and 

 slender, equalling the carapace in length, and distinctly denticulate. Supra-orbital 

 spines very small, and not defined from the base of the rostrum. Antennal spines well- 

 marked ; brauchiostegal projections exceedingly large, acutely triangular. The two 

 anterior caudal segments witli strong dorsal projections ; epimera small. Eyes very narrow, 

 cornea scarcely at all expanded. Antennal scale rather slender, terminal lobe small, outer 

 edge serrate in the distal part, spine of outer corner slightly projecting. Telson lingui- 

 form, apical projection quadridentate, having besides a small latei'al denticle. Length, 

 41 mm. 



Remarks. — This is a rather anomalous species, perha}>s most nearly related to 

 the species comprised in the first section, although the antennal scale is developed in 

 the same manner as in the species l)elonging to the second section. After all it 

 cannot be referred to either of these two sections, but should more properly i)e regarded 

 as the type of a third section, or subgenus. 



DefscrijHion.—Thv sole specimen obtained by the Challenger Expedition, and briclly 

 described by the late Dr. v. Willemoes-Suhm, does not appear to have been very carefully 

 handled, being in far from a good state of preservation, the carapace having been partly 

 crushed and disengaged from the body. It has therefore been somewhat difficult for me 



