576 Dr. R. von Willemoes-Suhm on Observations 



from a depth of 1900 fathoms. It is in so far remarkable as it was in 

 the Atlantic the only Schizopod in which the carapax is attached to the 

 posterior segments of the pereion. 



The most characteristic Schizopods in great depths belong to the Lopho- 

 gastridse, from which they differ, however (like Petalophthalmus from the 

 shallow- water Mysidae), by the looseness of the shield, and by a pair of 

 lateral eyes, which hitherto were only known among the Euphausiidae. 

 These lateral eyes, however, in Gnathophausia never exceed two in 

 number, and are invariably fixed on the- outer margin of the second 

 maxilla. The carapax here is bent backwards, and thus leaves a place 

 open, which enables these sense-organs to perform their duty. 



In all other respects these Schizopods are true Lophogastrids, some 

 of them, however, exceeding very much in size the small shallow-water 

 species (L. typicus) which Sars has described from the Norwegian coast. 

 There are three species : — 1. Gnathophausia gigas, length 142 millims., 

 found only once in the Atlantic from a depth of 2200 fathoms near the 

 Azores. It is not impossible that this is the animal which Dohrn has 

 got in a very badly preserved state from the coast of Africa (without any 

 appendages, and evidently somewhat crushed), and described under the 

 name of Lophogaster ingens. He does not, however, mention the eyes 

 on the second maxilla, and says that the carapax ivas fastened to the 

 pereion ; and for this reason I have to wait until I can myself compare 

 the specimen in the Hamburg Museum with those caught by us. This 

 would of course in no way affect the validity of the characters upon which 

 the genus Gnathophausia has been established, but induce one to put the 

 specific name of Gn. ingens, Dohrn, instead of Gn. gigas, mihi. 2. Gn. zoea, 

 a smaller form, length 60-80 millims. This species is the commonest Schi- 

 zopod, as we got it five times from 1000-2550 fathoms. Many males 

 and females have been caught, and its anatomy has been thoroughly 

 worked out. 3. Gn. gracilis, a still smaller spiny species, of which only 

 one specimen was got from 1500 fathoms, not far from the rocks of St. 

 Paul. 



A third genus in which the carapax is not attached is Chalaraspis, which 

 has got very long walking-legs with large claws to them (Ch. unguifer), 

 and is most nearly allied to the Lophogastridse, though it may perhaps 

 be necessary to establish for it a new family. Its organs of vision offer 

 nothing particular. I must refer about further details to my above- 

 mentioned paper, and can here only state that it was got four times, in 

 depths of 350, 675, 1850, and 1900 fathoms, in the Middle and Southern 

 Atlantic. 



Decapoda Macrura were very common : nearly every haul brought up 

 Peneids and Caridids, sometimes of large size and having often a very 

 peculiar look ; but I do not think that any thing very interesting, ex- 

 cept a series of new forms with a more or less spiny carapax and longer 

 or shorter legs than usual, will be found among them. 



