204 



Records of the Indian Museum. 



[Vol.. XIII, 



Including the new forms described below, ten species show- 

 ing affinity with L. styliferus are now known; seven of these are 

 dealt with in detail below. I have added an account of a ver\' 

 remarkable allied form which occurs in great abundance in Indian 

 estuaries in company with Leander . According to the methods 

 at present in vogue this species must be referred to the genus 

 Palaemon, but it bears such an exceedingly close resemblance to 

 L. styliferus that it may be doubted whether there is not some 

 error in our scheme of classification. I have called this species 

 Palaemon mirabilis. 



The principal characters of Leander styliferus and the related 

 species may be expressed in the following way : — 



I. Dactylus of last three peraeopods very long and slender, 

 that of fourth and fifth pairs at least as long as pro- 

 podus ; pleopods very long, those of first pair much 

 longer than carapace [carapace with branchiostegal 

 spine; palm of second peraeopods much swollen]. 



A. Last two pairs of peraeopods excessively long, 

 flagelliform, with dactylus much longer than 

 carapace ; carpus of second peraeopods much 

 more than half as long as palm. 



1. Basal crest of rostrum with at most 

 7 teeth ; fingers of second peraeopod more 

 than twice as long as carpus 



2. Basal crest of rostrum with 8 teeth ; 

 fingers of second peraeopod twice or less 

 than twice as long as carpus 



B. Last two pairs of peraeopods not excessively 



long, dactylus much shorter than carapace ; 



carpus of second peraeopods less than half the 



length of palm 



IL Dactylus of last three peraeopods not abnormal in 



length, shorter than propodus ; pleopods normal in 



length, those of first pair shorter than carapace. 



A. Carapace with branchiostegal spine; carpus of 

 second peraeopods less than one and a half 

 times as long as chela. 



I. Palm of second peraeopods much swollen 

 in large specimens, carpus much shorter 

 than chela. 

 (7. One or more subapical dorsal teeth 

 on rostrum ; carpus of second perae- 

 opods shorter than merus or than 

 fingers ; last abdominal somite in 

 adults not more than half length of 

 carapace, 

 i. Dactylus of third peraeopod 

 more than three quarters length 

 of propodus, that of fifth perae- 

 opod nearly half length of pro- 

 podus : last four abdominal 

 somites sharply carinate dor- 

 sally 

 ii. Dactylus of third peraeopod 

 scarcely half length of propodus, 

 that of fifth peraeopod at most 

 one third length of propodus ; 



temiipes, 

 Henderson. 



hastatns, 

 Aurivillius.i 



aiDiandalei, 

 sp. nov. 



carinattis, 

 Ortmann. 



1 I have not seen specimens of this species. 



