122 Dr. Strethill Wright's Observations on 



its summit (fig. 3) ; and it gradually assumed the structure of 

 that of the adult. 



The body of Ophryodendron frequently bears fusiform bodies, 

 from one to four in number, which I have already described, 

 and which appear to be gemmae. 



EXPLANATION OF PLATES IIL & IV. figs. 1-3. 



Pl.III. Two cells oi Sertularia pumila onvi\nc\\Ophryodendra&ve attached, — 

 the figure on the left side of the centre with gemma and contracted 

 proboscis, that on the right side of the centre with proboscis extended ; 

 the trunks of two others are shown in various states of extension. 



PI. IV. figs. 1-3. Young of Ophryodendron in various stages of development. 



On Dendrophrya radiata and D. ei'ecta (nov. gen. et sp.)*. 



The Rhizopodous animals to which I have given the name of 

 Dendrophrya are found plentifully on Sertularias, Flustras, Fuci, 

 and stones, in low-water pools at Granton Quarry, near Edin- 

 burgh. There are two species, D. radiata and D. ei'ecta. 



D. radiata. 

 Its general appearance is that of a small shelly mass, from the 

 borders of which radiates a system of bi-anched membranous 

 tubes, more or less coated with mud or other matters. In young 

 specimens the central shell is absent, and the animal presents 

 the appearance of an irregular system of branches radiating from 

 a centre. The shape of the adults is very various, and depends 

 on the surface to which they are attached ; they attain some- 

 times a diameter of nearly a quarter of an inch, though generally 

 much smaller. The shell is not acted on by acids, and is there- 

 fore silicious. The animal itself can seldom be detected, as it 

 lies concealed within its central flinty stronghold and the com- 

 plicated system of earthworks surrounding it. 



D. erect a. 

 In this species, found on stones, the branched, membranous 

 and mud-clothed tubes, instead of creeping over the surface to 

 which the animal is attached, spring upwards and outwards, as 

 in PI. IV. fig. 4. Delicate pseudopodia, linear or forked (figs. 4 

 and 5), are readily observed to protrude themselves from the ex- 

 tremities of the branches, accom])anied sometimes by lobular 

 processes of the sarcode of the animal. The patelloid shell of 

 D. erecta may be easily detached from its seat, and its tenant, a 

 small patch of semitransparent sarcode, scooped out with a flat- 

 pointed needle and transferred to the stage of the microscope. 

 It differs from the sarcode of other Rhizopods in being filled 



* Read to the Royal Physical Society of Edinburgh, April 24, 1861. 



