362 Prof. C. C. Nutting on 



Dimensions of the type (an adult male in spirit) : — 



Forearm 28 millim. 



Head and body 38 ; tail 32 ; ear 1 1 ; tragus on inner 

 edge 4'2 ; lower leg 13; calcar 12'5. Greatest length of 

 skull 12-1. 



Hah. Selangore, Malay Peninsula. " Caught under a 

 railway-arch." 



Type B.M. no. 98.3.13.5. Collected and presented by 

 Mr. H. N. Ridley. 



This little Pipistrelle is readily distinguishable from all 

 others by its short and peculiarly-shaped incisors, for all the 

 ordinary members of the genus have long styliform incisors, 

 which may or may not have a small supplementary cusp near 

 their tips, but which are never short, broad, and separated 

 into two almost subequal cusps, as is the case in P. Ridleyi. 

 The unusually short forearms, the wide space between the 

 canines and posterior premolars, in the centre of which the 

 small premolar stands, and the disproportionate size of the 

 last lower incisor are also all points distinguishing P. Ridleyi 

 from any other species known to me. 



In some respects, notably in the shortness of the forearm, 

 P. Ridleyi is approached by Temminck's " Vespertilio 

 temiis,^^ of which no authentic specimens are in the Museum 

 collection ; but Dobson's description of the teetii of that 

 animal, based on the types, shows conclusively tliat, wliatever 

 else it may be, it is not the little species discovered by 

 Mr. Ridley. 



LVIII. — On Three new Species of Hydro ids and One new to 

 Britain*. By C. C. Nutting, Professor of Systematic 

 Zoology in the University of Iowa. 



[Plates XIV.-XVI.] 



The material upon which the following descriptions are 

 based was obtained by me during April and May, 1895, whilst 

 occupying a table at the Laboratory of the Marine Biological 

 Association at Plymouth, the observations being made for the 

 most part on the living animal. 



Eudendrium album, sp. n. (PI. XIV. fig. I.) 



Trophosome. — Colony minute for this genus, matured speci- 

 mens measuring from ^ to f inch in height, llydrocaulus 

 * i'f. ' Journal of the Marine Biological Association,' vol. iv. 



