Boone, Crustacea, Cruise of "Alva," 1931 163 



ing a triangular tooth bent inward over the margin of the flat 

 main plate. The right half of the petasma is also oval, with the 

 outer lateral portion bent over, convex, forming a wide semitubu- 

 lar border, the free margin of which bears distally, near the point 

 of attachment, a series of three sharp triangular teeth, that inter- 

 fit with the opposed right side ; inside of this tubular region, the 

 main plate is flattish, and bears a strong longitudinal carina on 

 its surface ; the inner half of this plate becomes somewhat convex 

 toward the inner lateral margin and bears distally a small lobate 

 process. (See Plate 41, fig. D) . 



Genus: PALAEMONELLA Dana 

 Palaemonella longirostris Borradaile 



Plate 43 



Type : Mr. Borradaile's type came from Fadifolu Atoll, Mal- 

 dive Archipelago, and is deposited in the Cambridge Museum, 

 England, 



Distribution: Maldive Archipelago (Borradaile); Bali 

 (Boone). 



Material examined: One specimen from coral, Temukus 

 Roads, Bali, Dutch East Indies, October 25, 1931. 



Technical description : This species finds its nearest con- 

 gener in Palaemonella tridentata Borradaile, which comes from 

 the western Indian Ocean and Funafuti; from which it is dis- 

 tinguished by several valid characters. 



Palaemonella longirostris Borradaile has the carapace com- 

 pact, the surface smooth, firm, with the rostral crest arising two- 

 fifths of the carapace length from the posterior margin, the ros- 

 trum extending forward beyond the carapace as far as does the 

 scaphocerite. The antennular peduncle is only one-half the length 

 of the proportion of the rostrum. There are seven spines dorsally 

 in addition to the apex ; the distal third of the rostrum is upward 

 directed, the dorsal teeth are distributed : three on the carapace, 

 the most proximal and smallest tooth of the series being epigas- 

 tric ; the second and third spines are successively larger ; the 

 fourth, fifth and sixth spines are approximately subequal to the 

 second tooth and are regularly spaced along the proximal three- 



