BIOLOGY. 207 



mon crab of the oyster (Pinnotheres), had effected a lodgment in 

 the upper part of the intestine, which had thereby been greatly 

 distended in the form of a membranous cyst, attached to one side 

 of the shell, and extending around to the lower surface near the 

 mouth. The shell is usually swollen on the side over the cyst, 

 and the anal area is depressed and distorted, with a large orifice 

 passing obliquely into the cyst, out of which the crab may thrust 

 its legs at pleasure ; but it is apparently unable, when full grown, 

 to come entirely out. All the specimens examined in the c^yst 

 were females carrying eggs, but a very small crab found clinging 

 among the spines appears to be the male. The crab probably 

 effects an entrance into the intestine through the anus while quite 

 young, and, by its presence and growth in that position, causes 

 the gradual distortion of the shell and formation of the cyst. 



Another peculiar mode of parasitism was observed by him in a 

 singular crustacean (Hapalocarcinus marsupialis, Sampson) from 

 the Sandwich Islands. This creature lodges itself among the 

 slender branches of a coral (Pcecillipora ccespitosa, Dana), and 

 causes, probably by its incessant motions, the branches to grow 

 up and surround it, on both sides by flat expansions of coral, ter- 

 minating in digitations, which often interlock above, leaving 

 openings between them suitable for the uses of the parasite, but 

 usually too small to allow of egress. Most specimens of the 

 corals of this species sustain one or more, and often numerous, 

 examples of these curious enlarged bulbs among the branches. 



AXOLOTL A LARVAL SALAMANDER. 



According to M. Aug. Dumeril (" Comptes Rendus," Aug. 5, 

 1867), the Mexican axolotls, born in the Museum at Paris, un- 

 derwent a series of transformations, becoming yellowish-white in 

 spots, and losing entirely their branchial apparatus and the mem- 

 branous crest of the back and tail ; the internal organs experi- 

 ence changes comparable to those observed in the tailed batra- 

 chians when they pass from the larval state. Three of the arches 

 supporting the external branchiae disappear, while the most exter- 

 nal remains as the posterior articulation of the thyroid cornu ; the 

 anterior face of the vertebral bodies becomes less hollow ; and the 

 teeth on the vomer form beyond the internal orifices of the nasal 

 fossae an almost transverse row, which, with the absence of the 

 posterior palate teeth, is found only in the North American tritons 

 of the genus Ambystoma, of which the axolotl seems to be the tad- 

 pole or larval state. This confirms the opinion of Cuvier that this 

 animal, considered as a pereiimbranchiate batrachian, must be a 

 larva. He also found that the gradual, and even the sudden and 

 total excision of ail the external branchiae in the axolotl, obliging 

 them to respire through the pulmonary organs and the skin, did 

 not seem to cause any inconvenience to them, and many thus 

 mutilated underwent the above metamorphoses. 



NATIVES OF MADAGASCAR. 



Mr. Thomas Wilkinson, in the "Anthropological Review" for 



