Pam. 3, Plate 40. 



HERM^A DENDRITICA, Alder and Hancock. 



H. ovato-oblonga, postice attenuata, virescenti-alba, lineis viridibus dendriticis ornata : branchiis 

 elliptico-linearibus, viridibus, in seriebus 8 digestis : tentaculis validis, auriformibus : lateribus ante- 

 riofibus pedis subangulato-rotundatis. 



Calliopaa dendritica, Aid. and Hanc., in Ann. Nat. Hist., v. 12, p. 233. 



Hyb. On Codium tomentosum, near low-water mark, Torbay. 



Body three tenths of an inch long, greenish white, with dendritical green markings. 

 It is rather narrow behind the head, expanding towards the centre of the back and tapering 

 to a slender point at the tail, but all the parts are capable of great elongation and contraction, 

 and are sotaetimes very much attenuated. The sides of the body are depressed, and generally 

 overhang the foot. Head rounded in front, with a sub-velar margin curved inwards in the 

 centre towards the mouth. Tentacles rather large, auriform, arising from the sides of the . 

 head, and folded longitudinally ; they are somewhat dilated at the base, and slightly tapering 

 and rounded at the apex, towards which there are a few opake white spots : a line of green 

 runs up the back of each, which is branched at the sides. These lines unite with two principal 

 dorsal lines, which pass along the sides of the back, and terminate near the tail ; in front, the 

 latter divide into many branches over the head, and in their course backwards give off lateral 

 branches proceeding to the branchiae, and covering the sides with beautiful and delicate 

 ramifications. Other branches pass in various directions from the main trunks ; the whole 

 exhibiting a granular structure. Branchice long, and nearly linear when fully extended, 

 tapering gradually at the top, elliptic oblong when contracted ; the central vessel green and 

 lobated, giving them a transversely banded appearance : the outer sheath transparent, and 

 sprinkled over with opake white spots. The papillae are set in eight transverse rows, of 

 three or four each. Foot transparent white, tinged with green, rounded in front, slightly 

 produced and obtuse at the sides. It is rather broad, with nearly parallel sides, but 

 much attenuated posteriorly to the tail, which is often held in a curved position, and is 

 frequently much elongated. Dendritical markings are seen through the skin in the posterior 

 part. Anus forming a rather stout, conspicuous tube on the back, before the heart, and 

 not far from the commencement of the branchiae. The eyes are large, and situated a little 

 behind the tentacles. 



The heart pulsates ninety-six times in a minute. 



Nearly a hundred specimens of this beautiful and curious little creature were sent to us 

 by Mrs. Wyatt, from Torquay, in the summer of 1843, having been found by her on an 

 insulated piece of rock left bare at low tides in Torbay, feeding upon Codium tomentosum. 

 Unfortunately all the specimens were dead when they reached us, and the whole of the 



