98 J. Armstrong—A Description of some new Species of —[No. 2, 
tree-rat of India, called Mus rufescens by Blyth* and Jerdon,+ but greyer 
and less rufous than that species generally is. The skull is undistinguish- 
able from that of Calcutta specimens. The dried skin measures about 54 
inches from nose to insertion of tail, tail (vertebra preserved) 6 inches. The 
colour is greyish brown above, darker on the back owing to the prevalence 
of longer black-tipped hairs, white below, the edge of the white colour 
being distinct and well marked. 
This rat is found in most parts of India, and IL. robustulus,t of Burma 
appears to be only a variety. It also abounds in the Nicobar islands where 
it does much damage in the cocoa-nut trees.§ It is naturally surprising to 
find this rat in the upper Indus valley together with Central Asiatic types 
like Cricetus and Lagomys. Of course I do not mean to say that this long- 
tailed Indian tree-rat is true Dus rufescens of Gray, but the determina- 
tion of the names of Indian rats and mice can only be attempted after a 
careful comparison of specimens. 
—_ 
X.—A Description of some new Species of Hydroid Zoophytes from the 
Indian Coasts and Seas —By Suncuon J. Anmstrone, Marine Survey 
Department. 
(Received 7th May ;—read 4th June, 1879.) 
(With Plates IX, X, XI, XII.) 
With the exception of a single species all the following hydroids 
are calyptoblastic. The one exception is Hndendrium ramosum, which 
is a typical gymnoblastic zoophyte, and is especially remarkable in having 
the gonophores borne not upon a true blastostyle but upon atrophied 
hydranths from which the tentacles have disappeared. 
Laroia ELONGATA, (nov. spec.) 
(Plate 1X.) 
Zoophyte.—Plant-like, gregarious, dark-brown. 
Trophosome.—Stems erect, simple, straight or slightly curved, 1 to 
21 inches high, pinnate, with 3 or 4 transverse annular markings imme- 
diately above the origin of each pinna, and rooted by a creeping tubular 
* J. A.S. B., 1863, XXXII, p. 340. 
+ Mammals of India, p. 199. 
{ Blyth, J. A. S. B., XXVIII, p. 294; XXXII, p. 342; sco also J. A. S. B., 1878, 
XLVII, pt. 2, p. 165. 
§ Stray Feathers, IV, p. 433. 
