Trischizostoma 13 



Back broadly rounded. Kostrum broad, apically rouuded (Fig. 3). 

 Side-plate 2 the largest. Eyes very large. Antenna 1 in 9 , 1^* Joint large 

 in both flagella; in ö P* Joint of principal flagellum very large. Antenna 2, 

 ultimate Joint of peduncle in Q shorter than penultimate, in ö the reverse. Mouth- 

 organs in (Sars) : Upper lip long, naiTow ; lower lip with lobes acutely lanceolate. 

 Mandible, cutting edge very narrow, sharpened and obliquely truncated; 

 accessory plate inconspicuous; no molar; palp very large and densely setose. 

 Maxilla 1, inner plate small, unarmed; outer very narrow, apically divided 

 into small, claw-like teeth (4 stroug teeth, Bovallius); palp very minute but 

 distinctly biarticulate. Maxilla 2, both plates very narrow, stiliform. Maxillipeds, 

 inner plates very narrow, unarmed, 

 outer plates linguiform, partly en- 

 compassing the -other oral parts; 

 palp geniculate at the middle, 

 l^t Joint Short, 4*^ lanceolate. Mouth- 

 organs in cf (Bella Valle) : Upper 

 lip long, not narrow, apex not emar- 

 ginate; lower lip with broad lobes, 

 and a shorter pointed Single lobe 

 between them. Mandible narrowly LateraT^iew.'^LStrS'asars, 



spatulate, with out true cutting 



edges; no molar, 3 spinules; palp very large and setose. Maxilla 1, no 

 inner plate ; outer plate elongate, tipped with 5 large teeth ; palp reduced to a 

 little tubercle. Maxilla 2, iuner plate shorter and narrower than outer, apically 

 pointed, with one setule, outer apically broad, with 2 or 3 little setules. 

 Maxillipeds, inner plates very narrow, unarmed; outer plates as in Q, palp 

 with 1^* Joint longer than 2^ or 3^, 4*^ lanceolate. Gnathopod 1 enormously 

 developed, subchelate; in the adult of both sexes the band is so inverted, 

 that the finger seems to be attached to the wrong end of the palra. Uropods 

 with rami subequal, broadly lanceolate; outer ramus of 3'^ 2-jointed. Telson 

 small, entire. 



1 species. 



1. T. nieaeense (A. Costa) 1853 Guerinia nicaeensis, A. Costa, Descr. 3 Crost. 

 dal Hope, p. 3 , 1853 G. n., A. Costa, Fauna Reg. Napoli, fasc. Apr. 1853 p. 2 | 1867 

 G. n., A. Costa in: Annuario Mus. Napoli, v. 4 p. 44 t. 8 f. 1 | 1888 Trischizostoma n., 

 T. Stebbing in: Rep. Voy. Challenger, f. 29 p. 272, 1673 | 1861 T. raschii, A. Boeck 

 in: Forb. Skand. Naturf., Mede 8 p. 637 } 1872 T. r., A. Boeck, Skand. Arkt. Amphip., 

 V. 1 p. 97 t. 2 f. 1 I 1886 T. r., Bovallius in: N. Acta Soc. Upsal., ser. 3 v. 13 nr. 9 p. 24 

 t. 3 f. 41— 60 (?), 61—67 (<5juv.) ] 1890 & 95 T. r., G. 0. Sars, Crust. Norway, v.l 

 p.31 t. 12($); p.673 [ 1893 Guerina nicaeensis -\- T. r., A. Della Valle in: F.FI. 

 Neapel, t). 20 p. 776 t. 61 f. 10— 22 ((5); p. 780. 



Rostrum in § horizontal, in ä sKghtly depressed. Side-plates shallow, 

 1^* small, partly covered by the 2*^. Eyes almost meeting on the top of the 

 head. Antenna 1, 1^* Joint large, 2*^ and 3«^ short; flagellum in 9 9-jointed; 

 accessory flagellum subequal in length to 1^* Joint of primary, with 1 long 

 and 2 minute joints; flagellum in ö 8-jointed, 1^* Joint much larger than in 9 , 

 furnished with rows of hyaline filaments. Antenna 2 in 9 , twice length of 

 antenna 1; flagellum 24-jointed; flagellum in (5 60-jointed, twice length of 

 peduncle. Gnathopod 1, ß*'^ Joint greatly inflated, rounded triangulär, the long 

 palm armed with recurved teeth, those near the prominent prehensile angle 

 stronger and claw-like; 7*^ Joint strong, curved at the tip. Gnathopod 2 slender; 



