REPORT ON THE SCHIZOPODA. 23 



at the base, spear-shaped, more or less straight and horizontally projecting, and 

 terminating in a sharp jDoint. It has, also, three denticulate keels, one dorsal and two 

 lateral, a transverse section thus exhibiting a triangular form. Moreover, the dorsal 

 keel of the rostrum is produced posteriorly along the upper face of the carapace, being, 

 however, in some species interrupted in the middle part. It always reappears in the hind- 

 most region of the carapace, generally running out here as a more or less produced, 

 posteriorly directed, spine (the dorsal spine). The lateral wings of the carapace, too, in 

 some few species are produced as similar posteriorly pointing spines, very highly 

 developed in the form described below as Gnathophausia calcarata (see PL IV.); in 

 most of the species, however, these parts are evenly rounded off. 



The eyes in all known species are distinctly developed, although of somewhat 

 variable form, being sometimes very narrow, sometimes strongly dilated at the end, or 

 pyriform. On the upper side of the pedicle is invariably to be observed a small papiUar 

 prominence (the ocular papiUa). The eye-pigment is of a dark colour, and the visual 

 elements would seem to be normally developed. 



The antennular peduncle (see PI. VIII. fig. 1) is rather short and thick, though some- 

 what less so than in the two preceding genera. The basal joint is slightly flattened, and 

 projects on the outer side at the apex as an obtuse bristle-beset angle. The second joint 

 is very short, almost discoidal, with an elevated crest running transversely over the upper 

 side. The last joint, almost square in form, exhibits internally a sharpened edge, 

 that runs out anteriorly as a linguiform lobe fringed with strong ciliated bristles. On 

 the upper side of this joint, as in the Mysidse, between the insertion of the flageUa, 

 occurs a small scale-like projection, furnished with three delicate diverging bristles. 

 Of the flagella, the inner one is rather narrow, filiform, and of moderate length. On the 

 other hand, the outer one is most remarkably developed, as a rule equalling the 

 whole body in length ; it is distinctly compressed throughout, indeed almost riband-^ 

 shaped, and furnished with a dense fringe of sensory bristles along one of its margins. 



The basal part of the antennae (see Pis. II., III. fig. 4; PL IV. fig. 5; PL V. figs. 4 

 and 9; PL VI. figs. 3 and 9; PL VII. figs. 3 and 8) is, as usual, rather thick and massive,, 

 consisting of three segments, most distinctly defined below, the last of which runs out 

 externally as a compressed projection. The terminal part nearly equals in length the 

 inner antennular flagellum, its peduncle being rather small and divided into three 

 articulations, of which the last is the largest. The scale exhibits a somewhat different 

 appearance in the different species. Thus, in the three species, Gnathophausia ingens, 

 Gnathophausia gigas, and Gnathophausia calcarata, it is very small and in form some- 

 what resembles that of Lophogaster, whereas in the remaining species its structure is 

 more in accordance with that usually met with in the Caridea. 



The anterior lip (PL IV. fig. 4, L; PL VIII. fig. 2, L) forms a somewhat galeate or 

 triangular, fleshy prominence, placed posteriorly to the short epistome, at the anterior part 



