CRUSTACEA. 
311 
hmthmuhta off 8un(l(;rlaiul, and that Pcllognsiler (lA\\y') ifl gragariouflly 
parasitic on the pleon of Pagurus Icevis off Sunderland. New to Britain. 
Prof. Lilljeborg (/, c. p. 350) has also described Apeltes paguri, g. et sp. n. 
This nearly resembles in form Peltogaster paguri ; but it is more elongated, 
being 11 mm. long and 3| mm. broad, and differs also in the structure of the 
part by which it is attached to the Pagurus. And near the middle of the 
inferior surface, upon the paUium^ exists a large round aperture. The border 
of the chitinous membrane of the pallium surrounding this aperture is a little 
raised, horny and brown. It is by this border that the parasite is attached 
to the surface of Pagurus. 
Pycnogonidas. 
In adding this family to those of Crustacea, we do not consider 
that we are pledging ourselves bejmnd identifying it as a link 
that connects the Crustacea with the Arachnida. Although the 
result of recent research, both in the structure and development 
of these animals, tends to place them among the Arachnida, 
there are some points in their structure that associate them 
with the Crustacea ; this, together with old association, induces 
us to speak of them in this place for the present. 
Mr. Hodge (Trans. Tyneside Nat. Field Club, vol. vi. p. 195, 
or Ann. & Mag. Nat. Hist. xiii. p. 116) gives a list of the British 
Pycnogonoidea, with descriptions of several new species. There 
are twenty- two species in all : that is. 
13 species of Nymph(m, 
2 „ Pi llene, 
4 „ Phoxichilidium. 
1 species of Pasithoe, 
1 „ Phoxichilus, 
1 „ Pycnogonum. 
To these Mr. Hodge has added ten others, which are con- 
tained in the genera Ammoihoa (a genus not before represented 
by any British form), Achelia^ g. n., Pallene (pygmoia) y and 
Phoocichilidium (virescens) : 
Ammoihoa hrevipes, Hodge, 1. c. pi. 4. figs. 1-4, and A. longipes, Hodge, 1. c. 
figs. 6 & 6. 
Achelia, g. n., Hodge. This genus is distinguished by the possession of 
two pairs of palpi, one long and slender, the other short and stout. It may 
be thus characterized : — Antennae two-branched, one pair long and slender, 
eight-jointed ; the other pair short and stout, two-jointed, and produced im- 
mediately in front of the oculiferous tubercle. 
The author describes three species as new : Achelia echinata, A. hispida, 
and A. lervis ; the two last from the south coast of Cornwall, as well as Phoxi- 
chilidium vircsccns and Pallene pygma^a, a drawing of which was shown by 
Mr. Spence Bate as far back as 1853 to the meeting of the British Association 
at Hull, together with the larva of the same. This species has also been 
found by Mr. Hodge on the coast of Durham. 
