70 Transactions.— Zoology. 
Pleon with last segment large and triangular, emarginate at apex. 
Last pair of pleopoda single-branched, consisting of a single broad squami- 
form plate. 
This genus I have made for an Isopod of which I took several specimens 
at Timaru, and since then at Lyttelton Harbour. It will, I think, come 
nearest to Cassidina, Milne-Edwards ; however, it does not resemble C. typa 
so much as it does C. latisíiylis, Dana,* the figure of which I have been able 
to see through the kindness of Professor J. von Haast. According to Mr. 
Miers, C. latistylis is the same as C. emarginata, Guérin-Ménev., and is 
found at Kerguelen's Island. 
From Cassidina, however, my genus differs in having the last pair of 
pleopoda unibranched. In Cassidina the outer branch is present, but is 
almost rudimentary, while the inner and basal one is large and broad; so 
that Cassidina appears to be truly intermediate between Scutuloidea and 
some genus such as Zuzara, which has the two branches equally developed. 
Scutuloidea maculata, sp. nov. Pl. I., fig. 1. 
Head moderately large, transverse, about twice as broad as long, pro- 
duced obtusely between the bases of the antenne. First thoracic leg short 
and stout, second long and slender, the rest more like the first though not 
quite so stout, all having the propodos ending in two strongly curved claws. 
Segments of pereion subequal in length. Pleon of two segments, last large, 
triangular, with a wide shallow notch at apex. Last pair of pleopoda each 
consisting of a single broad squamiform plate, more than twice as long as 
broad, narrowing posteriorly, the inner edge conterminous with the side of 
the last segment of the pleon, and reaching very nearly to the end of pleon. 
Colour— pale yellowish-brown, whole body thickly covered with small 
purple spots. 
Length about à of an inch. 
Hab. Timaru, among seaweed at north side of the breakwater ; Lyt-- 
telton Harbour. 
Additional remarks on structure :— 
The eyes are moderately large and placed wide apart at the postero- 
lateral angles of the head 
The upper antenna (fig. 1a) is considerably shorter than the lower ; 
the three joints of the peduncle decrease in size distally and pass insensibly 
into the flagellum, which consists of but few joints. On the distal portion 
of it “ sensory sete” are found. These at first appear to be egg-cup 
shaped bodies, having a stout base from which arises all round a curved 
portion forming the cup. But careful focussing will show that there is 
* U.S. Exploring Expedition, 1852, XIV., Crustacea, part IL, 784; pl. 52, fig. 12. 
Trans. Royal Society, vol. 168 (extra volume), p. 204 
Hd 
