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



The first gnathopod (fig. 8), as well as the second (fig. 9), are terminated by a denticulated 

 claw, and covered by hairs at their inner side. It is quite certain that the gnathopods 

 (or the second and third maxillipeds) have no palpi. 



The pereiopods (fig. 1) are all terminated by chelae, but of very different sizes. The length 

 of the first pair, enormously developed, is 155 millims., thus exceeding by 35 millims. the 

 length of the whole body. The basal joint (the coxa) is very large and flat, the second, 

 however, very thin at its articulation, bent somewhat backwards, and increasing in size 

 only at its top, where it articulates with the broad base of the third joint. This is the 

 longest one, being covered on its upper surface by a series of small spines, and terminated 

 at its top articulation by two recurved spines. The fourth joint is again very slender ; 

 and so is also the delicate chela, the immovable finger of which is armed with a large 

 transverse spine. This first pair of pereiopods are perfectly smooth ; all the others, however, 

 are covered with hairs up to the top. They are much smaller and clumsier, the second 

 pair having only a length of 39 millims. At the coxal joint of the third pereiopod 

 are the genital openings. 



As to the underpart of the cephalothorax, it may still be mentioned that there is no 

 distinct opening for the so-called green glands, that there is a strong spine between the two 

 maxillipeds above the entrance of the mouth, and that an elevated line, covered with 

 a fringe of hairs, runs over the sternal shield between the first pair of pereiopods. 



The abdomen (pleon) has a length of 60 mm., and consists of six segments and the 

 telson. The top of the second to fifth segments is marked by a strong spine, which is 

 bent forward, and which in the first and sixth segments is only represented by a small ele- 

 vation. There are also in the first segment no squamiform lateral appendages, which in 

 the subsequent ones are very large, but decrease in size from the second to the sixth. All 

 of them are fringed with long hairs ; and so are also the telson and the caudal appendages, 

 the form of which can best be seen from Mr. Wild's excellent drawing. 



The first pair of pleopods is transformed to styliform appendages (fig. 2), our specimens 

 being both males. The four subsequent ones have a length of 33 millims., and are evi- 

 dently very powerful organs of locomotion. They consist (fig. 3) of a very strong basal 

 joint, to which the external palpus is attached, of smaller second joint, which goes 

 laterally over into the second interior palpus, and of a very small and styliform third 

 joint (fig. 3, a) — quite the same arrangement which we find in W. crucifera and in an un- 

 described Palinurid from the deep sea near the Bermudas (fig. 12) . All the four pleopods 

 are alike ; and the posterior ones are very little smaller than the anterior ones. 



Of the internal organization I can only say that the carapace is wonderfully trans- 

 parent for the size of the animal, and permits the heart to be seen, which is situated 

 just between the hepatic and stomachal regions. 



2. Willemoesia crucifera, n. sp. (Plate XII. fig. 10, and Plate XIII. figs 10 and 11.) 

 The species we have hitherto considered is very delicate, and has very long fringes 

 of hairs on the legs, the carapace, and the pleon. All this is less the case in the 

 smaller species, which is much more solid, not transparent at all, and in which the 

 fringes are not so large and beautiful. Nevertheless also this one is a very elegant 



