THE GBAPSOID CKABS OF AMERICA. 7 



fingers, or digits, the narrow scissorlike blades of the claw end of a cheliped, 

 the movable finger being the dactylus, the immovable finger the terminal 

 part of the propodus. 



Flagcllum of the antennae and antennules, the long, narrow, terminal portion, 

 composed of numerous short segments. 



Oastric region, the large median area, bounded behind by the cervical suture, 

 outside by hepatic regions, and anteriorly by the fronto-orbital regions. 

 It is divisible into the following subregions or lobes: Mesogastric, proto- 

 gastric, epigastric, metagastric, and urogastric. 



Hepatic region (paired), a small subtriangular, antero-lateral region, wedged 

 between the branchial and gastric regions and either the margin of the 

 carapace or the margin of the orbit. 



Interantennular septum, the plate which separates the two antennular cavities 

 from each other. 



Intestinal region, a short transverse area behind the cardiac region. Some- 

 times called the posterior cardiac lobe. 



Ischiunt, or ischiopodite, the third segment (from the body) of a leg or ruaxilli- 

 ped. It is usually the first large segment of the maxilliped. 



Jugal region. See Pterygostomian region. 



Labial border, the anterior border of the buccal, or mouth cavity. 



Manns, or palm, the broad, proximal part of the propodus of a cheliped. 



MaxilUpcds, the three outermost pairs of jaw-feet, the third or outer pair form- 

 ing more or less of an operculum to the buccal or mouth cavity. 



Merits, or meropodite, the fourth segment (from the body) of a leg or maxilli- 

 ped. It is usually the first long segment of a cheliped, or walking leg. 



Mesogastric lobe or subregion, the median division of the gastric region, pen- 

 tagonal in form and with a long, narrow, anterior prolongation. 



Metagastric lobes, the postero-lateral iobes of the gastric region ; often not 

 defined. 



Orbital hiatus, the gap in the orbital margin at its lower, inner angle. 



Orbital region, the narrow space bordering the upper margin of the orbit; 

 not always distinguishable. 



Palp, or palpus, of maxilliped, consists of the last two or three segments fol- 

 lowing the merus-joint. 



Pereiopods, a term applied to the chelipeds and four pairs of legs. 



Pollcx, the immovable finger of the cheliped. The term " pollex " has been 

 used, however, by some writers, for the movable finger, a use not without 

 justification. 



Propodus, or propodite, the sixth or penultimate segment of a leg or maxilliped. 

 In a cheliped, the pi-opodus consists of the palmar portion or manus, aud a 

 narrower, immovable finger. 



Protogastric lobes or subregions, the aiitero-laterul lobes of the gastric region. 



Proximal, nearest the center of the body ; opposed to distal. 



Ptcrugostomian region, the triangular space on the ventral surface of the 

 carapace, on either side of the buccal cavity. Sometimes called the jugal 

 region. 



Rostrum, or front, that part of the carapace which projects forward from 

 between the bases of the eyestalks. 



Sternum, or sternal plastron, the ventral, segmented wall of the thorax. 



Stridulating ridge or organ, a ridge or surface made up of a close series of 

 cross ridges or tubercles, so placed as to rub against another surface and 

 thus produce a noise. 



Subequal, nearly equal. 



