472 CRUSTACEA MALACOSTRACA. 



Kroy. ; Petalophthalmus W.-Suhm. P. armiger. Male with greatly developed 

 mandibular palp, and small dorsal shield. Eyes blind, curved and flat- 

 tened. N. Atlantic, 100-2,500 fathoms. Boreomysis Sars, deep sea ; 

 Siriella Dana, thoracic appendages with claws, endopodites of abdominal 

 legs with peculiar spirally curved (branchial ?) processes. Pelagic. 



Fam. 2. Lophogastridae. Cuticle calcified ; thoracic legs bear gills, 

 and their bases are covered by the edges of the dorsal shield ; otolithic 

 vesicle absent, brood lamellae on seven thoracic legs. Lophogaster M. 

 Sars, rostrum short, antennal scale broad. L. typicus M. Sars, a 

 bottom form in N. and S. Hemispheres. Ceratolepis Sars. Gnathophausia 

 W.-Suhm, rostrum long, spear-like, outer flagellum of anterior antennae 

 as long as body. Several spp. from deep sea. G. ingens Dohrn, attains a 

 length of over 6 in. from tip of rostrum to that of telson. G. drepanephora, 

 off W. coast of Ireland ; Chalaraspis Sars, dorsal shield overlaps the 

 anterior abdominal segments. One specimen from l,800fthms. S. Ocean. 

 Eucopia Dana. E. australis Dana. Four anterior thoracic appendages 

 modified as maxillipeds, the three succeeding pairs very long and directed 

 forwards. All seven armed with a small prehensile claw ; 8th shorter. 

 Widely distributed in deep water. 



Order 3. CUMACEA.* 



Malacostraca with a small cephalothoracic shield and four or 

 five free thoracic segments, the first, second and third thoracic limbs 

 are maxillipeds, the first bearing respiratory lamellae, and two or 

 more succeeding pairs of legs are biramous ; the, abdomen is slender 

 and elongated, and generally bears, in the male, two to five pairs of 

 swimming feet besides the caudal (6th) appendages, which are alone 

 present on it in the female. 



The Cumacea are small marine animals frequenting the 

 neighbourhood of muddy and sandy shores, though they extend 

 also into deep water. For our knowledge of their anatomy 

 we are mainly indebted to G. 0. Sars. They are in many 

 respects intermediate in character between the Amphipoda and 

 Isopoda on the one hand, and the Schizopoda on the other. 



The integument is firm and brittle, and the body divided 



* H. Kroyer, Om Cumaceernes Familie, Naturh. Tidskr., 1846. A. 

 Dohrn, Ueber Bau. u. Entw. d. Cumaceen, Jen. Zeits., T. v, 1870. H. Blanc, 

 Dev. de 1'oeuf et formation d. feuillets primitifs chez la Cuma Rathkii, 

 Rec. Zool. Suisse, II, 1885. H. J. Hansen, Isopoden, Cumaceen u. Stomato- 

 poden d. Plankton-Expedition, 1895. G. O. Sars, An account of the 

 Crustacea of Norway, III, Cumacea, Bergen, 1900. Caiman, W. T. The 

 Marine Fauna of the W. Coast of Ireland, pt. IV, Cumacea, Fisheries, 

 Ireland, Sci. Invest., 1904, I (1905). Id. Cumacea of ihe Siboga Exped. 

 Leiden, 1905. 



