197 . 



less expanded, and separated by a deep incision. Mandibles rather simple 

 in structure, forming strong curved lamellse without any trace of palp, cutting 

 edge rather broad, wanting a molar expansion, but having on the left side 

 a small accessory lamella. Maxillae comparatively very large; 1st pair 

 with the basal lobe short and broad, palp generally small; 2nd pair with 

 the lobes divaricate, and rather dissimilar in shape, the inner being much 

 broader than the outer, which is linear and more or less elongated. Maxil- 

 lipeds originating from a common very narrow basal part, masticatory lobes 

 generally greatly expanded, palp slender and atteiiuated. Gnathopoda, as a 

 rule, slender and feeble, not subcheliform. Pereiopoda normal, antepenirlti- 

 mate pair having always the basal joint narrow linear, last pair generally 

 shorter than the others, with the basal joint laminai'ly expanded. Branchial 

 lamellae simple ; incubatory lamellse rather large. Uropoda subsimilar, succes- 

 sively diminishing in length, with the rami lanceolate. Telson rather short. 

 Remarks. — This is a very distinct family, exhibiting, as it does, 

 but few characteristics in common with those treated of in the preceding 

 pages. In their outer habitus, the forms under question show perhaps, by 

 their smooth compact body, a remote resemblance to some of the Lysianas- 

 sidse; but in the anatomical structure, they are widely diiferent. The family 

 comprises as yet 5 genera, 3 of which are now for the first time established. 



Gen. 1. StegOCephaluS, Kroyer, 1842. 



Body stout and compact, quite smooth, with rather firm integuments, 

 and with the anterior part of tlie back boldly curved. Cephalon very short, 

 its lateral parts to a great extent covered by the 1st pair of coxal plates, 

 front more or less produced in the form of a curved rostrum, lateral corners 

 distinctly projecting. First pair of coxal plates oblong triangular, terminating 

 in an obtuse point, the 2 succeeding pairs rather narrow, but deeper than the 1st; 

 -Itli pair strongly developed, forming posteriorly a large expansion, the 

 inferior edge of which is evenly curved; 5th pair obliquely oval, and 

 scarcely deeper than tlie succeeding ones. Eyes wholly wanting. Antennae 

 rather robiist, tlie superior ones with the ])eduncle sliort and stout, 

 flagellum multiarticulate, and provided posteriorly with fascicles of 

 delicate sensory bristles, accessory appendage biarticulate, with the ter- 

 minal joint extremely small. Epistome flattened in front. Anterior lip 

 deeply bilolied, the lobes somewhat unequal. Posterior lip with the lateral 



