Crangonyx 371 



Body compressed, not carinate. Side-plates 1—4 deeper than the 

 following. Eyes present or absent. Antenna 1 tho longer, accessory flagellum 

 small, 2-jomted. Mouth-parts imperfectly known, probably near to those of 

 Niphargus (p. 405), but (in C. flagellatus) lower lip with very small inner lobes, 

 maxilla 1, inner plate with 6 setae, maxilla 2, inner plate partially fringed 

 on inner margin, maxillipeds, outer plates narrow. Gnathopods 1 and 2 

 subchelate, ^^^ Joint not strikingly broader than 5*^^. Peraeopods 3 — 5, 2*^ Joint 

 moderately expanded. üropod 3 not elongate, with single 1-jointed ramus. 

 Telson entire or partly cleft. 



6 accepted species, 1 doubtful. 

 Synopsis of accepted species: 



^ f Uropod 3, peduncle shorter than ramus 1. C. subterraneus . p. 371 



\ Uropod 3, peduncle longer than ramus — 2. 

 Telson not cleft — 3. 

 Telson more or less deeply cleft — 5. 



Telson more than twice as long as broad .... 2. C. flagellatus . . p. 371 

 Telson less than twice as long as broad — 4. 



Apex of telson with shallow sinus 3. C. vitreus . . . . p. 372 



Apex of telson slightly arcuate 4. C. tenuis . . . . p. 872 



Uropod 3, ramus more than half length of peduncle 5. C. bifurcus . . . p. 373 

 Uropod 3, ramus less than half length of peduncle 6. C. recurvus . . . p. 373 



1. C. subterraneus Bäte 1859 C. s., Bäte in: P. Dublin Univ. zool. bot. Ass., 

 V. 1 p. 237 I 1862 C. s., Bäte, Cat. Amphip. Brit. Mus., p. 178 t. 32 f. 6 1 1893 C. s., A. 

 Della Valle in: F. Fl. Neapel, v. 20 p. 681 \ 1896 C. s., Vejdovsky in: SB. Böhm. Ges., 

 nr. 10 p. 5. 



Side-plates 1 — 4 moderately deep, 4*^ the largest, slightly excavate 

 behind. Pleon segments 1^ — 3, postero-lateral corners seemingly obtusely 

 quadrate. Eyes imperfectly formed, showing small iiTegular patches of lemon- 

 coloured pigment. Antenna 1 about V4 length of the rest of the animal, 

 1^* Joint as long as 2<^ and 3*^ combined, flagellum as long as peduncle, 

 about 1 1-jointed. Antenna 2 more slender. Gnathopod 1 stouter but 

 shorter than gnathopod 2, b^^ Joint about as broad as 6*^ but rather shorter, 

 6*^ quadrate, palm slightly convex, not very oblique. Gnathopod 2, 5^^ Joint 

 much longer than broad, 6*^ longer but scarcely broader, fusiform, palm very 

 oblique, ill-defined. Peraeopods 1 and 2 much more slender than the 

 following, which are successively longer, with well expanded 2"* Joint. Uropods 

 1 — 3 reaching nearly equally far back, üropod 1, rami equal, rather shorter 

 than peduncle. üropod 2, rami equal, subequal to peduncle. üropod 3, ramus 

 about twice as lon"g as the short peduncle. Telson narrow, entire. L. 5 mm. 



England (well in Hampshire). __ 



2. C. flageUatus Benedict 1896 C. /"., J. E. Benedict in : P. U. S. Mus., v. 18 p. 616. 



Side-plates 1 — 4 moderately deep. Pleon segment 3, postero-lateral 

 corners obtusely quadrate. Eyes wanting. Antenna 1, 1^* Joint rather longer 

 than 2^, 2* nearly thrice as long as 3*^, 3*^ thrice as long as broad, flagellum 

 sometimes as long as body, reaching 61 joints. Antenna 2 shorter, ultimate 

 and penultimate joints of peduncle long, subequal, flagellum reaching 19 joints. 

 Upper lip broadly rounded, longitudinally carinate. Lower lip, inner lobes 

 small. Mandible, cutting edge and accessory plate dentate, accessory plate 

 slighter on right mandible, few spines in spine-row, molar prominent, sti-ong, 

 palp, 2^ and 3* joints large, subequal, well armed. Maxilla 1, inner plate 



24* 



