48 THE VOYAGE OF H.M.S. CHALLENGED. 



the several other parts show auy essential difference from what is observed in that 

 species. 



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

 Samboangan, Mindanao (Pliilippine Islands). 



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

 green mud. 



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

 distinctly projecting. Dorsal keel interrupted anteriorly. Supra-orbital spines small. 

 Antennal scale jointed at apex, outer edge jutting out anteriorly into a strong spine. 

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

 united on the ventral face. 



11. Gnathophausia gracilis, Willemoes-Suhm (PL VII. figs. G-10). 



Gnathophausia gracilis, Siibm, Trans. Linn. Soc. Lond. (Zool.), ser. '2. vo). i. p. 33, pi. ix. 



fig. 1, 1875. 

 Gnatliojiltausia gracilis, G. C>. Sars, Preliuiinary Notices on the Challenger Schizopoda, No. 11. 



Specific Characters. — Form of body very slender. Carapace not very large ; dorsal 

 spine short, but distinctly projecting; iufero-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. Eostrum 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 ; branchiostegal projections exceedingly large, acutely triangular. The two 

 anterior caudal segments with 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 lateral denticle. Length, 

 41 mm. 



Remarks. — This is a rather anomalous species, perhaps 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 belonging to the second section. After all it 

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

 as the t}'pe of a third section, or subgenus. 



Description. — The sole specimen obtained by the Challenger Expedition, nnd briefly 

 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 



