CRYPTOTHIRIA. 257 
ISOPODA., BOPYRID. 
NORMALIA., 
Genus—CRYPTOTHIRIA. 
Cryptothir. Dana (1852). 
Liriope. RaruKkeE (1843, not Liriope of Lesson.—G. Meduse, 1839.) 
Liriopsis. Scuuttzn, Wiegm. Arch. 1859, p. 310. 
Cryptoniscus. Frivz Miter MSS. 
Hemioniscus. Bucwuouz. 
THE animals of this genus differ from those of most of 
thegenera of Bopyride inthe nature of their habitats(being 
parasitic on crustaceans that are lower than themselves in 
the natural classification) as well as in their structure ; 
the supposed males, or at least the young, bearing a much 
stronger resemblance to the young than to the full-grown 
male Bopyri, whilst the females appear to be entirely 
destitute of antenne, legs, branchial lobes, or other 
appendages. 
The supposed males and young are very minute, oval 
or elongate in form, convex, with the head and segments 
of the body and tail distinct, the former semicircular, 
provided with two eyes and four antenne, of which the 
anterior pair are very minute and slender, whilst the 
posterior pair are greatly elongated, being about half 
the entire length of the animal, composed of three or 
four moderately long basal joints, followed by a multi- 
articulate flagellum, of which the first articulus is the 
largest. The parts of the mouth have not been deter- 
mined, but they appear to be covered by a large square 
pair of plates (maxillipeds), of which the lower margin is 
serrated, or possibly only fringed with hairs. Each of the 
VOL. II. s 
