CRUSTACEA. 19 



below, fingers gaping, the lower one curved, with closely-set teeth at one end, but without 

 teeth at the base ; upper one with several teeth at the end, a large, thick tooth near the base, 

 and a deep sinus between them ; third joint of the hind-legs with two tubercles on the upper 

 surface near the base ; second pair of legs longer than the others. 

 Hab. Philippine Islands. 



In this species the sides are armed with four broad, rounded teeth placed before the 

 lateral spine, while in M.porcettus there is but one tooth anterior to the spine, and in M. tuber- 

 culatus there are two large, prominent teeth ; the carapace is more elongated in the males 

 than in M. porcellus or M. tuberculatus, the frontal spine is much longer, and the tubercles 

 on the back are smaller and less rounded. The young female of this species appears to be 

 the M. diadema, Leach, MSS., where the carapace is subtetragonal, nearly as wide as long, 

 strongly embossed with numerous tubercles of different sizes, and with the frontal spine short 

 compared with the male and adult females. 



2. MEN^ETHIUS POKCELLUS, Adams #• White. 



Thorace trigonali, longiore quam latiore, antice producto, postice rotundato ; parte superiore coniplu- 

 ribus, magnis, rotundatis tuberculis obsita ; lateris margine una, valida spina, magno, obtuso, conspicuo 

 dente ante spinam; lateribus post eanthos angustatis. 



Fronde tribus dentibus ex eadem planitie surgentibus ; medio admodum elongato, acmninato, ad finem 

 inclinato, longitudine fere tertia parte thoracis, setis curvatis ad utrumque latus ciliato, velut in Huenia ; 

 spinis lateraJibus admodum validis et acutis, ad utrumque latus prorsum directis ; basi pedum duobus vel 

 tribus tuberculis in latere exteriore ; secundo pari ceteris longiore. 



Hab. Mauritium. 



Carapace trigonal, longer than wide, produced anteriorly, rounded behind, upper part 

 very irregular, and covered with numerous large, rounded tubercles ; side-margin with one 

 strong spine, with a large, blunt, conspicuous tooth before it ; sides narrowed behind the orbits. 



Front with three teeth arising from the same plane, the middle one very much elongated, 

 pointed, bent down at the end, about a third the length of the carapace, ciliated on both sides 

 with curved setae, as in Huenia ; the lateral spines very strong and sharp, directed forwards 

 on either side, base of legs with two or three tubercles on the outer side, second pair longer 

 than the others. 



Hab. Mauritius. 



m 



The existence of a single well-formed, strong tooth, situated anterior to the lateral 

 spine, serves to characterize this species. 



3. MEN.ETHIUS TUBERCULATUS, Adams % White. 



Thorace subtrigonali ; lateribus duobus, depressis, angularibus dentibus ante spinam lateralem, quae 

 obtusa est. Regione cardiaca et ventriculari duobus antice tuberculis, uno ad utrumque latus lineae mediae ; 

 crista verticali tuberculo minuto, altero post admodum prominente et rotundato, et tertio post alteram 

 paullo minore ; posteriore thoracis margine duobus, erectis, angularibus dentibus. 



Fronte tribus spinis ex eadem planitie surgentibus ; media longa, gracib, inclinata atque in medio 

 sulcata ; spinis laterakbus altioribus validis, triangularibus, duobus inter eas parvis tuberculis. 



Hab. Mauritium. 



