2 



Eusiroides 345 



3. Gen. Eusiroides Stebb. 



1888 Eusiroides, T. Stebbiug in: Kep.Yoy. Challenger, v.2d p. 969 | 1893 E., 

 G.O.Sars, Crust. Norway, ».1 p.414 j 1893 iJ., A. Della Valle in: F. Fl. Neapel, v. 20 p. 671. 



Body with rouuded back, not carinate. Side-plate I distally widened. 

 Calceoli present on autennae 1 and 2 in p ; accessoiy flagelluiu of antenna 1 

 'consisting of 1 narrow short Joint. Maxiila 1 with 1 — 3 setae on inner 

 plate, 10 spines on outer. Maxilla 2 with varying proportions of the 2 plates. 

 Gnathopods 1 and 2, 5*^ Joint short, cup-shaped, attachment of 6^*^ normal, 

 ßth large, oval, palm ill-defined except by spines, finger long, curved. 

 Peraeopods 1 — 5 rather robust, 3^—5*^ with 2*^ Joint large, broadly oval. 

 In other respects scarcely differing from Eusirus (p. 338). 



3 species accepted, 1 obscure. 



Synopsis of accepted species : 



j Pleon Segments, postero-lateral margin not serrate 3. E. crassi p. 346 



\ Pleon Segment 3, postero-lateral margin serrate — 2. 



( Eyes dark-coloured I.E. raonoculoides . p. 345 



i Eyes light-coloured 2. E. dellavallei . . p. 346 



1. E. raonoculoides (Hasw.) 1880 Atylus m., Haswell in: P. Linn. Soc. 

 N.S.Wales, vA p.327 1. 18 f. 4 ^ 1888 A. m. -(- Eusiroides caesaris -\- E. pompeii, T. Stebbing 

 in: Rep. Yoy. Challenger, v.29 p.969; p.970 t.88; p.974 t.89 | 1893 E. m. + E. c. (part.), 

 A. Della Valle in : F. Fl. Neapel, v. 20 p. 674, 672. 



Pleon Segments 1 and 2 dorsally produced to a small acute tooth, 

 which is sometimes obsolete. Head, rostrum small, lateral corners rounded. 

 Pleon Segments 1 and 2 sharply quadrate or a little produced, segment 3 

 with postero-lateral margin very couvex, serrate with 10 — 18 upturned 

 teeth. p]yes very large, reniform, nearly meeting above, blue-black. Antenna 1, 

 1^* Joint as long as or longer than 2^ and 3^ combined, 3^ less than half 

 as long as 2*^, both these and flagellum calceoliferous, flagelluro nearly 

 twice as long as peduncle, attaining 74 joints, the proximal broader than 

 long, closely set with calceoli, many at intervals distally widened, terminal 

 joints slender, without calceoli. Antenna 2 rather shorter, ultimate Joint of 

 peduncle calceoliferous, a little or scarcely shorter than penultimate, flagellum 

 sometimes as long as peduncle, attaining 54 joints, arranged and armed as 

 in antenna 1. Maxilla 1, inner plate carrying 2 setae, 1^* Joint of palp 

 more than half as long as 2'^. which caiTies many setae on the outer 

 margin. Maxilla 2. inner plate broader than outer, and not shorter. Gnatho- 

 pods l and 2, b^^^ Joint spinöse, 6*^ broadly oval, narrowest at hinge of 

 finger, with transverse gi'oove on outer surface near the base, palm long, 

 convex, defined by transverse line of sti'ong palmar spines on inner surface, 

 palm border striated, set on both sides with spines and spinules, finger large, 

 curved, with channelled inner margin. Gnathopod 2 rather the larger. 

 Peraeopods 1 — 5 rather robust, carrying many short spines, finger short 

 and stout. Peraeopods 3 — 5, 2^ Joint well expanded, peraeopods 4 and 5 

 rather longer than 3*. üropods 1 — 3 spinöse, in uropod 1 outer ramus a 

 little, in uropod 2 much shorter than the inner, which exceeds all the rest 

 in length. Uropod 3, rami subequal. Telson rather long, tapering, cleft 

 about to the middle, lateral margins slightly sinuous near base, apices 

 narrow, bidentate. Colour light olive, with a few red spots on the antennae. 

 L. 6 — 18 mm. 



South-Pacific and southern Indian Ocean (Port Jackson, Jervis Bay and Melbourne, 

 [Australia]; Heard Island). 



