﻿CRUSTACEA JIALAC(JSTRACA. II. 



The chelipeds are somewhat difficult. In Aps,iid,s a clioHpcd seems to consist of only five 

 joints instead of seven phis claw. lint the presence of an exopod on the first joint ])roves that it is 

 the .second (according to the earlier morpholo<;y), and from a comparison with the .second pair of leo-s it 

 is evident that the lon<^- joint preceding the chela has been formed h\' the complete fusion of two 

 joints; finally, the movable finger of the chela answers to the "claw" in the following leg.s, thus con- 

 sisting of seventh joint and the real claw. In most genera of Tanaidie the chelipeds con.sist of the 

 same five joints as in . [psmdrs, but in several forms, as in the male of Ncolaiiais gigaiitcns, in Crypto- 

 copc I'orii/gii and C.arctopliyhi.x and above all in .li/nr/I/nini (cnuii). vSars' figures) we find a cous]iicuous 

 piece developed as a .separate plate or (in Aiiartlinira) a large real joint between the usual "first" 

 joint and the body; this plate or joint is certainly the real first joint which in most forms of the 

 order is feebly or not marked off from the cephalothorax. As the chelipeds show sucli tangled 

 morphology I have abstained from apphing the counting method when the joints to be described 

 must be indicated. Therefore I use some of the natnes applied b\- H. Milne-Edwards to the joints of 

 the legs in Decapoda; whether most fif the joints in the legs of Tauaidacea and Decapoda can be 

 considered identical as to morphological \-alue according to their number is another and ver\' difficidt 

 question not to be discussed here. The appareuth- first and very cons]iicuous joint of the chelipeds 

 in most forms is named the basal; the real first joint \\\ Annrthiitni and the plate marked off in the 

 forms just enumerated is named the coxal joint. The joint bexond the basal is named the ischium, 

 but in most forms it affords no character worth mentioning. The next joint is named the car]) us, 

 though morphologicalh' it answers to meros and carpus; in the descriptions of the chela I speak of 

 hand and fingers, the hand going to the insertion of the movable finger. 



F. On generic and specific Characters. 



In this report I establish only three genera, all belonging to the Tanaidse. Two of these are 

 well separated, but the tliird, founded on a single specimen, was established only because it fits badly 

 in the genera known, though it does not seem to possess an\' single realh' good generic character. 

 The big genus Pi-ptoi^initl/ia is di\-ided into groups, and in the future it will certainly be divided into 

 three or four genera, but I think it better to postpone this splitting up until a good number of 

 unknown forms have been discovered, because the Carcinologist will then be more able to settle the 

 \-alue of several characters, whether they may be considered of generic or onh' of specific valiu\ And 

 here we fall in with a difficulty. It is with good reason that vSars laid stress on the mouth-]>arls in 

 females (and immature males) as affording generic characters and especialh' on the dex'elopment of 

 the mandibles and the shape of their molar process, if that is present. I!ut of numerous new species 

 the material is \'er\' scantx or e\'en consisting of oul\ a single specimen, and in such cases an e.vam- 

 ination of the mouth-iiarts was postponed. Furthermore man\ species arc so small, that several 

 Carcinologists dealing with such animals are scarcelv abk- lo dissect the mouth-parts in such a wax- 

 that a good representation of \.\\v mandibles can be gi\en. .\ud by the t'xamination of the mouth- 

 parts in \-arious sjjccies ^A I .rploi^iKit liia I found that two such s]H-cies as A. ,i7//>fri/^/'^///,s' n. sji. and /.. rvv/- 

 Irnlis n. sp., which are rather allied in most characters and ma\ be referred to the same group, show 



111.- Diuiisl, Inocll-l-vpo.iilioii. 111. J. 2 



