1903.] FRESHWATER CRAB FROM UPPER GUINEA, AT 
Measurements in nrillimetres. 
Perea ei al gl @ 
aban ios Galrd. |S 
| 
Breadth of the cephalothorax ...............0..sc0cee eee .-| 67 |58 |51 | 483) 34) 53 
Length of the cephalothorax without the abdomen...) 45} | 39 |385 |33 | 24+) 39 
Distance between the external orbital angles ......... 40% | 354 | 31 | 303/23 | 32 
* posterior epibranchial teeth ...)574|50 | 434 | 423 | 314] 433 
Breadth of the anterior margin of the front............ }18 |16 | 14 |i4 | 103) 14 
Distance, in the median line, between the anterior : 
margin of the front and the postfrontal ridge ...... 6 | 5 | 45) 4 | 83] 43 
Distance between the outer angle of the orbits and ; 
UieMpOstivOn bale Ges ee clececeaaecceeeees- aickaes: 5y| 43] 46) 4 | 382) 38h 
Distance between the outer angle of the orbits and 
the posterior epibranchial tooth ......................55 10 3s | OF) 7e| 54) 6S 
Breadth of the urogastric ares) 2.0... ..cc.cccsesssesace ses 11 8k] 7 6s} 44] 7 
a 99 CATING ANGI Goi iivcccceeecetnereecnsaeene-| a) [12° || 10%) 10° || 751 9 
55 NO OMAIIES recdascs csedPennebe seareGeosciacee ag a bLAR PREY ailamtcy all mtsteal Wats) alpiarsy 
Height of the orbits, near the lower internal angles .| 6 | 5% 5 + | 32/1 6 
Length of the terminal segment of the abdomen...... 7) be 4A, 
» penultimate segment .............0..0005 63 6 44 
Breadth of the anterior margin of this segment ...... 81 | 72 5 | 
33 » posterior margin of it soriceal| pan |) MOP El eos |) st 
Length of the larger chela ................c.csseeceeee-2-- 45 146 | 39 31} | 223 | 34 
- of) TEENA ” oon nan eresaqucd nec boucdeele GOMER Cea RB IG Ce, Wien si tal eo) al (gl ced bal OYE wl bn IC) 
Height of the palm, near the articulation of the 
GLYCHAVJNEIS: sco shoo neo nde nstined doeebee a Mbet sce COI A CERES ae AB Mane CAO a Racy al Letlccy alfa ayo al amp 3 
Length of the legs of the penultimate pair ............ 86 |76 |71 |66 |50 | 80 
ss » meropodites of the penultimate pair...)27 | 25 | 235/21 | 16} | 27 
Breadth _,, 35 ‘3 43 AS call tek || Shall Nels 5] 8h 
Length of the propodites ss S » ---|16 |13 |124)12 | 94) 154 
Breadth _,, » ” » oo >| 6 5z| 53) 4 67 
Length of the dactylopodites ,, Bs 5) ---| 208 | 17 | 164) 154) 112118 
5 By ees) On Gheplastipaiceaeancrserereetres| Cou Olio ole (99) 1160 
= » meropodites of the last pair ............|214]193/18 |164/13 | 20 
Breadth ,, : PP an sip Seo ouGeal ha tesenl |e Clos Ih a Aat ae Véos IN (tats 
Length of the propodites __,, a eeeceeens es | (La LO RN OS.) ORM NR lO 
Breadth ,, ae ef a Sosessancesal i | Ger INGE | ERNE 
Length of the dactylopodites ,, 53 sonccnosocee| I SMA Wale aloes |) fs} haat 
Nos. 1-3, River Prah; Nos. 4, 5, Liberia; No. 6, type-specimen of Thelphusa 
africana A. M.-E., Ogoué, from the Paris Natural History Museum. 
EXPLANATION OF PLATE IX. 
Figs. 1-6. Potamon (Potamonautes) latidactylum, n. sp—Fig. 1. Dorsal view of 
the anterior part of the carapace of the largest male specimen from the 
River Prah, X 13. Fig. 2. Left antero-external angle of the carapace of 
the young male from Liberia, xX 8. Fig. 3. The same of the young female 
from Liberia, x 3. Fig. 4. Abdomen of the largest male from the River 
Prah, X 1}. Fig. 5. Larger chela of the same male from the River Prah, 
x 14. Fig. 6. Smaller chela and carpus of the adult female from the 
River Prah, x 1}. 
Figs. 7-9. Potamon (Potamonautes) africanum A, M.-E., female type-specimen of 
the Paris Museum, from Ogoué.—Fig. 7. Dorsal view of the anterior part 
of the cephalothorax, x 1}. Fig. 8. Left antero-external angle of the 
carapace, X 3. Fig. 9. Right chelipede, x 1}. 
