588 Dr. R. von Willemoes-Suhm on Crustacea 



perhaps most the genus Typhimeclia. I shall therefore give later a 

 more accurate description of them, and here only direct attention to the 

 fact that in the deep sea, as ivell as in the sedimentary strata, animals are 

 found which, compared ivith their relations living noiv-a-days and in shalloiu 

 water, are of a very considerable size ; and I may perhaps best in this place 

 add that in this dredging of 1375 fathoms a Nymphoid (Pycnogonid) 

 was got measuring nearly two feet across the leys. 



The Schizopods appear to gain most by the deep-sea investigations ; for 

 strange forms have been discovered by us as in the Atlantic, and strange 

 forms continue to come up as we go on with the researches in the other 

 oceans. The Chalaraspis unguifer, which constitutes a new family (as 

 has been shown in my paper on the Atlantic Crustacea) allied to the 

 Lophogastrida?, and characterized by the presence of all the pereiopods, 

 the looseness of its dorsal shield, the absence of accessory eyes, &c, 

 is one of the characteristic members also of the antarctic deep-sea fauna. 

 It was got in these dredgings, as well as in those on our way from the 

 Antarctic to Australia, when another new genus of this family came up, of 

 which I shall speak afterwards. In these trawlings near the Crozets Ave 

 got another Schizopod, a new species of my genus Petalophthalmus, first 

 found in the tropical deep sea of the Atlantic. It is a form differing 

 from the Mysidae by the looseness of its dorsal shield, by large plate-like 

 duplicatures of the chitinous substance in the place where we are accus- 

 tomed to find the eyes, and by the presence of breeding-lamellae at the 

 base of all the pereiopods. I must refer for the details to my previous 

 paper, where I have discussed its zoological position and its nearest rela- 

 tions, and may here only repeat that the male of the Atlantic species 

 P. armiger, v. W. S., differed very much from the female and showed 

 characters hitherto never found in a Schizopod. Its first antenna, palpi 

 mandibulares, maxillipeds, and first gnathopods are transformed into very 

 powerful prehensile organs. In this species, which is much larger than 

 the Atlantic one (length of the female 62, of the male 55 millims.), nothing 

 of the kind exists. The male is only a little smaller than the female, has 

 of course no breeding-lainellse, and is only distinguished by the presence 

 of two small recurved tubes, situated behind the last pair of pereiopods, 

 and having evidently the function of copulative organs. Besides the 

 pleopods are larger than in the female, and have, as is the case in many 

 Mysids, got two rami. I shall call this species Petalophthalmus inermis, 

 as the chief difference from P. armiger consists in the resemblance of the 

 male to the female and in its size. The parts of the mouth as well as the 

 other appendages are very much alike in both species. Drawings of 

 most of them have been made, and will be published on a later occasion. 

 As we got many specimens of this larger species, I examined the curious 

 petaliform organ which morphologically represents the eye, and found 

 that it consists of nothing but a double chitinous layer, which contains a 

 small quantity of muscular tissue. 



