Urocaridella

Wang, Yan-Rong, Chan, Tin-Yam & Sha, Zhong-Li, 2015, A new deep-sea species of the genus Urocaridella (Crustacea: Decapoda: Caridea: Palaemonidea) from Yap Seamount in the Western Pacific, Zootaxa 4012 (1), pp. 191-197 : 196-197

Key to species of the genus Urocaridella

1. Third abdominal somite produced posteriorly into a large triangular cap overhanging fourth abdominal somite; distal margin of telson bearing two pairs of spines; fingers of second pereiopod much shorter than palm................... U. liui sp. nov.

-. Third abdominal somite with dorsal margin at most slightly produced posteriorly, not overhanging anterior part of fourth abdominal somite; distal margin of telson bearing three pairs of spines; fingers more or less as long as palm in second pereiopod............................................................................................ 2

2. Telson terminating posteriorly in narrowly triangular endpiece; mandible with well-developed 2- articulated palp; first pereiopod with fingers longer than palm, chela more than twice as long as carpus; second pereiopod with fingers considerably longer than palm, palm longer than carpus; third pereiopod with propodus less than three times as long as dactyl; fourth and fifth pereiopods with propodus less than four times as long as dactyl..................................... U. urocaridella

-. Telson with posterior margin rather simply triangular without narrow endpiece; mandible with vestige of pale or none at all; first pereiopod with fingers subequal to palm in length, chela much shorter than carpus; second pereiopod with fingers more or less subequal to palm in length, palm no longer than carpus; third pereiopod with propodus at least four times as long as dactyl; fourth pereiopod with propodus more than four times as long as dactyl; fifth pereiopod with propodus more than five times as long as dactyl......................................................................................... 3

3. Branchiostegal spine removed from margin by more than length of spine; fifth abdominal somite rounded poster-ventrally.. 4

-. Branchiostegal spine removed from margin by no more than length of spine; fifth abdominal somite strongly acute poster-ven- trally..................................................................................... U. vestigialis

4. Third abdominal somite without rounded ridge medially, with nearly subrectangular dorsal profile......... U. antonbruunii

-. Third abdominal somite with prominent, rounded ridge medially, subrectangular in profile.................... U. pulchell