30 DR. R. V. WILLEMOES-SUHM ON SOME ATLANTIC 



side of which is densely covered with hairs (fig. 3, mp). The palpi are situated on both 

 sides of the upper lip, and reach higher up than the funiculus of the exterior antenna. 

 The first pair of maxillae could not he inspected, as they are entirely covered by the second 

 pair, which, like the whole oral apparatus, have a strong resemblance to those of Lopho- 

 gaster (Sars, fig. 28, cd). All the parts mentioned there are also to be found in our case 

 (fig. 3, mx) : — on the inner side the two digitiform manducatory processes covered with 

 stiff hairs; close to them on both sides a fiagellum (fig. B,f), which is jointed in Gna- 

 thophausia ; and on the outsides the palpus (fig. 3, p) in the form of a large leaf -like 

 appendage fringed with hairs and occupying, like a large cover, the whole space between 

 mandibles and maxillipeds. Prom the basal joint of these maxillae start a pair of small 

 black pigmented accessory eyes, the peduncles of which have a length of 2 millims. 

 Their position and direction are such that they just peep out between the inferior mar- 

 gin of the dorsal shield and the gnathopods. A dissection of these accessory eyes is 

 of course impossible in our case ; but I think one is right in supposing that they consist, 

 like the accessory eyes of the Euphausiidse, of a lens, nervous rods, and a pigmented sub- 

 stance. They have been found in the Euphausiidse on the basal joint of the pereiopods, 

 as well as of the pleopods, and in Thysanopoda norvegica even up to the number of eight 

 pairs. In Lophogaster there are none, nor have accessory eyes ever been observed on the 

 maxillse of any animal. 



There is only one pair of maxillipeds, as there is in Lophogaster; and in both the 

 gnathopods are used for walking. On the large transverse basal joint of the maxillipeds 

 we have a long flattened palpus (PI. IX. fig. 16, p), and somewhat further on a small 

 flagellum (fig. 16,/). The second and third joints of these maxillipeds are very short ; 

 the fourth is longer, the fifth very short again ; and the sixth is the terminating claw. 



Gnathopods, Pereiopods, and JBranchice. 



We have remarked already that the gnathopods do not essentially differ from the perei- 

 opods, and are used for walking. At the base of all of them, with the exception of the 

 last pair of pereiopods, are the arborescent gills, the branches of which are partly situated 

 underneath the lateral parts of the dorsal shield, partly projecting into the water. There 

 are, as far as I can see without dissecting or spoiling our specimen, three branches, one 

 of them on the sides, one between the legs, and a larger one leaning on the pectoral shield, 

 which is entirely covered by two rows of branchiae. In the whole the arrangement seems 

 to me to be exactly the same as in Lophogaster ; and the pictures given by Sars (figs. 16, 

 35, 37, and 45) give also a very fair idea of the branchial appendages of Gnathophausia. 



The gnathopods and pereiopods (PL IX. figs. 8-14 may be compared here, though these 

 figures are drawn from Gn. zoea) consist each of seven joints, if one counts that basal one 

 to which the branchiae are attached. To the second joint the palpi are attached, which 

 differ somewhat from those of Lophogaster ; they are shorter, and in Gnathophausia 

 the ramus palpi rapidly decreases in width, and has a great resemblance to the ramus of 

 one of the pleopods. The palpus of the first pereiopod has a length of 13 millims. The 

 third and fourth joints are in all the legs very short, and do not offer any thing parti- 

 cular ; but the fifth and sixth are very different from each other in different legs. In 



