186 Bulletin Vanderbilt Marine Museum, Vol. VI 



trigonal, the inner lateral face much smaller than the other two, 

 which are rather convex ; the carpus is subconical, widening dis- 

 tally with the upper outer distal margin excavate ; the propodus 

 is about three and one-half times the length of the carpus, with 

 the palm much dilated, about two-thirds of the total propodal 

 length ; most dilated proximally, the greatest height being 0.4 of 

 the length, the least height 0.3 of the length ; the fingers are both 

 decidedly deflected, the upper one being the more down-curved; 

 the lower finger down-curved and also incurved, the tips conspicu- 

 ously overlapping ; the cutting edge of the lower finger is sinuate, 

 with a small basal molar, followed by a wide concavity, into which 

 the very large, median molar of the upper finger fits, and beyond 

 this concavity is the large, wide, triangulate tooth, the outer mar- 

 gin of which slopes toward the acuminate tip of the finger. The 

 above mentioned median, acuminate-triangulate molar of the up- 

 per finger is the only tooth it has, the remainder of the margin 

 being sinuate-laminate. 



The ambulatories are moderately stout, subcylindrieal. The 

 first pair of ambulatories measure as follows: ischium, 2 mm. 

 long; merus, 2.5 mm. ; carpus 1.8 mm. ; propodus, 2.8 mm. ; dactyl, 

 0.19 mm. long; the upper dactyl margin is very curved, termi- 

 nating in an acute hook, the lower lateral margin is concave, with 

 a median, curved hook, which is subequal to the upper distal hook ; 

 beyond the median hook the inferior angle is a blunt node which 

 supports a tuft of coarse bristles. On the third pair of legs this 

 basal node is relatively larger than on the two preceding pairs 

 of legs. 



The abdominal terga are especially broad in the female, with 

 the epimeral region deep, forming a capacious brood pouch, which 

 holds seventy-five to a hundred young. 



References: Pontonia biunguiculata, Paulson, 0., Crust. Red 



Sea, 1875, p. Ill, figs. 1, la-u. 

 Pontonia tridacnae, Henderson, J. R., Trans. Linn. Soc. London, 



ser. 2, Zool., vol. V, 1893, p. 438. 

 Conchodytes meleagrina, Pearson, J., Rept. Ceylon Pearl Oyster 



Fish, and Marine Biol., pt. 4, 1905, p. 77.— NoBiLi, G., Ann. 



Sci. Nat. Zool. Paris, ser. 9, t. IV, 1906, p. 77 (part) . 

 Conchodytes hiunguiculatus, Kemp, S., Rec. Indian Mus., vol. 



XXIV, 1922, p. 280, text figs. 103a-d. 



