188 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. [1885. 



Bate incorrectly gives "Fabr." as authority for tlie name membra nucea, 

 and, apparently not having- read Pbilippi's desciiptiou, misapprehends 

 the structure and purpose of the anteuunlar flagella. 



Xiphopeneus Smith. 



This genns, which has been united with Penwtis by Miers and Kings- 

 ley and is not referred to by Bate, is apparently a valid one. It differs 

 from the three genera already defined in the great length of the fourth 

 and fifth peneopods, of which the pn)i)odi are raultiarticulate and tlagel- 

 liform, as in Benthcecetes. [This is characteristic of the female as well 

 as the male.] It agrees with Fencvus and Parapenwus and differs from 

 Hymcnopenams in the form of the mandibular paJpus. It agrees with 

 Farapencvus and Hymenopenanis and differs from Fencvus in the short and 

 unsegmeuted endognath of the first maxilla and in having no branchiae 

 on the fourteenth somite; and it agrees with Hymenopenccus and differs 

 from Fenam.s and Farapenccus in the long flagella of the antenuula?. The 

 branchio-epipodal formula is the same r»s in Farapenceus constrictns. In 

 the type species the epipod of the maxilliped is i)rolonged in a slender 

 but not segmented tip, and there are exopods at the bases of all the 

 l)eraeopods. 



Xiphopeneus Kroyeri. 



Pcnceu.8 Kroyeri Heller, Sitzungsber. Acad. Wiss. Wieo, xlv, jj. 425, pi. 2, 



tig. 51, 1862. 

 Xiphopeneus Havttti Smith, Traus. Conn. Acad., ii, p. 28, pi. 1, figs. 1-1&, 1869. 



I have seen only the type specimens of my X. Rarttii. 



Aristeus ? foliaceus. 



? Fenccus foliaceus Heller, Stizuugsber. Akad. Wiss. Wien, xlv, p. 424, 

 pi. 2, fig. 50, 1862. 



Station 13143, March 23, 1884, Gulf of Darien, north latitude 9° 30' 45", 

 west longitude 76° 25' 30", 155 fathoms, green mud. One male (7264). 



This specimen represents a species congeneric with my Aristeus ? 

 tridens^ but specifically very distinct from it. I refer it doubtfully to 

 the Mediterranean species described by Heller as Fencvus foliaceus, 

 although it .agrees well with the outline figure of the carapax and the 

 short description given by that author. 



The carapax is similar to that of A.% tridens, but the rostrum is 

 longer and armed with many more teeth, there is a well-developed 

 hepatic spine, and the anterior margin retreats very much more from 

 the antennal to the branchiostegial spine. The rostrum is longer than 

 the rest of the carapax, with a high dorsal crest extending further for- 

 ward than in J..? tridens and armed with five long spiniform teeth 

 directed forward, of which the second is highest and over the posterior 

 part of the margin of the orbit, and the fifth considerably in front of 

 the eye, while the terminal portion of the rostrum beyond the fifth 

 tooth is nearly straight, directed slightly upward and armed with four 



