138 



CRUSTACEANS OF THE 



three terminal joints are moreover more orless tomen- 

 tose along their margins and the dactylopodites and pro- 



podites are unarmed, devoid of spines (Fig. 1 7*). 

 Measurements in mm. : 



Distance between the external orbital angles . . 10 8^ 10^ 10 9^ 



Greatest width of the cephalothorax 11 9| 11,V 11| 10',- 



Length , „ « 9 7f 91 9 8J 



Breadth of the upper margin of the front. . . 5| 4,',- 5 J 5| 5 



Height of the front in the middle IV 1^ 1| 1| 1^ 



Breadth of the posterior margin of the cephalothorax. 6 5^ 7 6j 6^ 



Length of the terminal segment of the abdomen. I'i 1| 



» » » penultimate segment Ij li. 



Breadth of the anterior margin of this segment. 2 1| 



» ;/ // posterior „ , „ » . S'f 3^ 



Horizontal length of the chela 7 4^ 6 5^ B', 



" " fingers ^ 2f 3| 3' 3i 



Height of the hand 3| If 1^ 14 1\ 



Length of the meropodites _^ C 8 H '''ï 7' 



Breadth „ » v C^ c- 2| 2^ 3 2| 



Length of the propodites <o S 5i 5', 53^ 5 



Breadth, „ , .S J li. IV IV IV 



Length of the dactylopodites .... .J •^ 51 5| 5 4J 



Breadth » » » «*- S :i » :» 1 



o &. "5 Ï T ï 



lerseke, May 1899. 



List of all the species of Potamon Sav. (inclusive Para- 

 thelphusa H. M. E.) described up to the present time, May 1899 '). 



1) This List was published already last year in: Annali del Museo Civico 

 di Storia Nat. di Genova, Ser. 2, Vol. XIX, 1898, p. 435, of course without 

 the Borneo-species described in this paper. 



The african species are printed in italics. The three following, a description 

 of which has never appeared as far as I know, are nomina nuda and are not 

 mentioned in the List. These species are Pot. gracilipes White 1847 from the 

 Philippine Islands and furthermore Fot. granidostim Marts, and Pot. Schwein- 

 furthi Marts., two species quoted by Hilgendorf (^Monatsberichte k. Akad. d. 

 Wiss. Berlin, 1878, p. 802). 



As habitat I have only quoted the locality indicated in the first description 

 of the species. 



Notes from tlie Leyden Museum, "Vol. XXI. 



I 



