30 



antenna? shorter than the inferior, accessory appendage well developed, with 

 the 1st joint laminar. Oral parts greatly projecting inferiority and crowded 

 together in the form of a trifid tube. Epistome not projecting. Anterior lip 

 very elongated and narrow; posterior lip with the lobes acutely lanceolate. 

 Mandibles with the masticatory part styliform produced, cutting edge very 

 narrow, sharpened and obliquely truncated, molar expansion quite wanting, 

 accessory lobe inconspicuous, palp very large and densely setons. First pair 

 of maxillae with the masticatory lobe very narrow and divided at the tip 

 into small claw-like teeth, basal lobe small, unarmed, palp very minute, but 

 distinctly biarticulate. Second pair of maxillae with both lobes very 

 narrow, styliform. Maxillipeds rather large, masticatory lobes lingniform, 

 projecting inferioiiy and partly encompassing the other oral parts at the sides, 

 basal lobes very narrow, unarmed, palp genicnlate on the middle, with the 

 terminal joint lanceolate. Anterior gnathopoda enormously developed, prehensile, 

 terminating with a very large subchelate hand, which in the adult animal 

 becomes inverted in such manner, that the dactylus originates from the infero- 

 posterior corner of the propodos and is bent forwards against the strongly 

 denticulated palm. Posterior gnathopoda quite of the structure typical to 

 the Lysianassidae. Pereiopoda not very large, the joints more or less compressed 

 and only beset with very minute and scattered spines. Branchial lamellae 

 very large and of irregular form. Incubatory lamellae rather broad and 

 fringed with numerous slender setae. Pleopoda very powerful. Uropoda with 

 the rami broadly lanceolate and almost bare, last pair with the outer ramns 

 biarticulate. Telson small, entire. 



Rrmurl-*. - In classing this remarkable form, I have seen n't to dissent 

 widely from the views supported by earlier authors. Boeck regards this ani- 

 mal as the type of a distinct family (Prostomatae), which he places at the 

 head of his division (rdiniiniriiifi, immediately before the OrcJirxfiidfr, and 

 Dr. Uovallius has classed it, together with the genera Synopia Dana and 

 Zfy/wr/oyWx G-. 0. Sars, within a distinct tribe, Synopidea, constituting, however, 

 within the latter, a particular family, Trischizostomatidce. Finally Prof. Lillje- 

 bnrg considers it the type of a subfamily, Trischisoztomathia, placing it in the 

 vicinity of his sub-family Plioxma, Although Boeck has mentioned some points 

 of agreement with the Lyssianassidae, none of these authors would seem 

 to have recognised the near relationship, which in fact exists between this 

 iniiiial and the true Lysianassidae. The agreement is indeed so very close, 

 tlmt the present form, in my judgement, unquestionably ought to be classed 

 within the very same family. The oral parts have not yet been exactly 

 examined in their details, neither by Boeck, nor by Dr. Bovallius. Though 

 ;i1 lirst sight very anomalous, they art- found, on a closer examination to be 



