656 



CRUSTACEA. 



alike, in the several species discovered, in being rounded behind and 

 set around with spinules. Besides the claw terminating the thoracic 

 le-s there is a number of short setae, about as long as the claw, or 

 somewhat exceeding it in length. The mandible has a rather small 

 molar extremity, and bears a three-jointed palpus. The inner maxillae 

 are oblong lamellar; they bear a tuft of setae at apex, and also a 

 lateral branch, which is short and furnished with a few setae. The 

 outer maxillae or maxillipeds consist of a short basal joint, hardly dis- 

 tinct; a broad lamellar joint, which narrows upward; and a third 

 joint, which is oblong, and in one species appeared to be three-jointed. 

 The second joint of the organ has two lobes or plates on its inner side, 

 and just exterior to it, there is an oblong lamella, which proceeds from 

 the first or basal joint of the organ. The eyes are large globular, 

 with a short pedicel. One of the flagella of the first antennae is stout- 

 ish and pubescent at base. The inner caudal lamella contains near 



base a small oval, transparent gland. The palpus of the thoracic legs 



has a very broad, oblique, round-obovate basal joint. 



In two species, an oblong oval gland was observed in the thorax 



(see fig. 6, pi. 43, and fig. 1, pi. 44), which was very large in females, 



and probably, is ovarian in function. 



SlRIELLA VITREA. 



Carapax fmnte obsolete triangulatns, angulo wfero-antico aeutus sed non 

 productus, wfero-postico rotundatus. Ocidi maximi orbiculati. teg- 

 mentum abdominis posticum spimdis ceque circumdatum y laminam 

 caudalem externam fere cequans, interna multo brer las. Antemiarum 

 basis extemarum basi internarum valde brevior. Pedum rami thora- 

 cicorum ino?qui. 



Carapax very low triangular in front, acute but not prolonged at 

 lower anterior angle, rounded behind. Eyes very large orbicular. 

 Last abdominal segment set around evenly with spines, the seg- 

 . ment about as long as outer caudal lamina and much shorter than 

 the inner. Base of outer antennae very much shorter than that of 

 inner. Branches of thoracic feet unequal. 



Plate 43, fig. 6 a, animal, enlarged; b, lateral view, more enlarged ; 



