KEPORT ON THE SCHIZOPODA. 21 



slender, spear-shaped, three-edged, (U'liticuhitc IliudcT part of carapace f(jr the most 

 part drawn out dorsally into a posteriorly pointing spine. Caudal segments narrow, with 

 small, bilobed epimera ; the last subdivided transversely. Eyes well developed, with a 

 small papilla issuing from the pedicle anteriorly. Antennular peduncle short and thick, 

 outer flagellum greatly produced, riband-shaped. Antennal scale of somewhat varying 

 form in different species. First pair of maxillae provided with a biarticulatc, setous palp, 

 completely recurved, posteriorly. Second pair exhibiting at the base exteriorly a pigmented 

 protuberance (luminous organ ?) ; anterior masticatory lolje cleft to the base int(j two 

 very narrow lappets ; palp rather large. Maxillipeds having exopodite either very small 

 or entirely wanting. Legs slender, nearly uniform, ambulatory; first pair differing very 

 slightly from the rest. Branchia3 divided into four bipinnate ramifications, pinnulse 

 exhibiting irregularly disposed, digitiform lobules. Telson very large, constricted near 

 the base, lateral edges densely spinulous, apex armed with two strong curved spines con- 

 nected at the base. Uropoda with the outer plate broader tliau the inner, and having a 

 short dentiform projection at the end of the outer margin, the terminal lobe being marked 

 off by a distinct transverse suture. 



Remarks. — Of the earlier known Schizopods, Lophogaster certainly comes nearest to 

 the present interesting genus, first established by the late Dr. v. Willemoes-Suhm, 

 and I fully agree with that author in including it in the same family with that 

 genus. On the other hand, it will appear from the diagnosis given above, that the 

 genus here treated of exhibits several very striking features, distinguishing it rather 

 clearly from the other Lophogastridfe. Moreover, the' general appearance will be found 

 to diverge a good deal from that observed in the two preceding genera. 



To our knowledge of the present remarkable genus a very important contriljution has 

 been fui'nished by the Challenger Expedition, no less than nine different species being 

 represented in the collection. Of these species, only one, Gnathophausia ingens, had 

 been recorded at an earlier date ; all the remaining species were first discovered during 

 the course of the Expedition. 



With a view of obtaining a clearer survey of the organisation of this interesting type, 

 I have deemed, it advisable to give a general description of the genus, previously to 

 characterising the several species comprised therein. 



General Description of the Genus. — The form of the body (see figures given in Pis. II. 

 to VII.) wiU be found to vary somewhat in the different species, mainly owing to the more 

 or less prominent development of the carapace. In all the species, however, the tail is 

 very slender, almost cylindrical in form, and its segments provided with rather small 

 epimera, divided into two more or less produced lappets. The last segment exhibits, as 

 in Lophogaster, an obliquely transverse suture, thus apparently subdividing it into two 

 sections, the anterior of which is provided with a pair of imperfectly developed, and, in 

 some species very peculiarly formed, epimera. 



