Sentence:  It is however to be remarked, that these hairs are not of a <WSD>spinous</WSD> nature, as in the Mus fasciculatus and the Mus macrourus; they may properly be compared to bristles, having more consistence and rigidity than those of the Mus decumanus and giganteus; and in a natural arrangement, our animal stands between these species, and between those from which the character of the section is derived by M. Desmarest, and which, in a more rigorous sense, may be called spinous Rats. 
Meaning of the word marked with <WSD> tags:  Spine-like; spiny.