Dr. J. E. Gray on Carpenteria and Dujardinia. 381 



III. Tail oblong, compressed, covered with separate three-keeled 

 scales; tip covered with a small compressed cap-shaped spinose 

 shield. — Plectrurina. 



4. Plectrurus. 



Tail oblong, compressed, covered with separate three-keeled scales; 

 apex furnished with a small compressed cap-shaped shield, covered 

 with small spines, and ending in a central perpendicular spinose 

 keel. Nose rounded, rather produced. The central ventral series 

 of scales rather broader than the other scales, six-sided. 



1. Plectrurus Perrotetii (fig. 3). 



Pale brown (in spirits), paler beneath, with a more or less large 

 and distinct oblong transverse yellow spot in front of the vent. 



Plectrurus Perrotetii, Dum. & Bib. Erp. Gen. vii. 167. t. 59. f. 4, 



skull; t. ya. f. I. 



Hab. Madras {J. C. Jerdon, Esq., 1846) ; " Neelgherries." 



Var. I. With a series of obscure small pale spots between each 

 series of the dorsal scales. 



Var. 2. Tail with a central line of white spots on the upper side, 

 and with a row of white spots on each side near the vent, converging 

 and united in the middle of the end of the tail ; hinder part of upper 

 lip white. 



Var. 3. Scales of the tail nearly smooth ; in other specimens these 

 scales are very distinctly three-keeled. 



We have a smaller specimen of this animal, which we received 

 from the Fort Pitt Museum, as having been sent by ^Ir. Ford 

 from the Cape of Good Hope ; but as they had many specimens 

 from India in that Museum, 1 suspect this habitat is a mistake, as 

 the genus has not yet been received with certainty from Africa, and 

 it is scarcely likely that an Indian species should be also found in 

 that country. 



On Carpenteria and Dujardinia, two genera of a new 

 FORM OF Protozoa with attached multilocular Shells 



FILLED WITH SpONGE, APPARENTLY INTERMEDIATE BE- 

 TWEEN Rhizopoda and Porifera. By Dr. J. E. Gray, 



F.R.S. ETC. 



Many years ago 1 observed on some specimens of Cardita varie- 

 yata, which I\lr. J. Ritchie, the late Consul of Tripoli, had collected 

 at Marseilles and sent to the British Museum, some specimens of a 

 parasitic shell which resembled a Balanus in shape, but when more 

 carefully examined were evidently not formed in the same manner 

 as the shells of that class of animals ; as however they were not in a 

 good condition, it was not easy to decide from what animal they 

 derived their origin. 



Mr. Cuming some years later, when he transmitted his collection 

 of Cirripedes to Mr. Dawson for examination, sent with them some 



Ann. 6c Mmj. N. Hist. Ser. 3. Vol. ii. 26 



