DECAPODA. 
369 
zoophytes, algae, &c., may thus be found. JBalani occasionally cover the 
entire upper surface of the body of the crab. 
Aug,. 22, 1840. — On opening a thornback (Raid clavata), about 20 inches 
in length, caught in Belfast Bay, I found its stomach entirely filled with 
S. phalangium. 
S. tenuirostris, Leach. 
On examining some fine Stenorhynchi dredged in Belfast Bay, from a 
depth of 20 to 23 fathoms (shelly sand), in Oct., 1846, by Mr. Hyndman, I 
found that like specimens obtained there, but from a much less depth, some 
years before, had more characters in common with this species than with 
S. phalangium. The rostrum, though longer than in the latter, — 3 lines 
in length in a specimen whose carapace from its base to the hinder ex- 
tremity is 10 lines, — is not of the extreme length of that of S. tenuirostris: 
— instead of being “ longer than the peduncle of the external antennae,” 
it is not so long. But “ the series of minute spines on the inner part of 
the arm, the body altogether more elongated, and the spines more acute,” 
than in S. phalangium, mark my specimens as S. tenuirostris. 
The preceding notes were made on a comparison of these examples 
with the descriptions of Leach and Bell. Having subsequently taken 
specimens to London and compared them with those in the British 
Museum described by Leach, the result was the same. I therefore look 
upon S. tenuirostris and S. phalangium — although extreme forms are very 
distinctly marked — to be in reality but one species. It may be added, 
that in one of the two Irish examples of what I have called S. tenuirostris 
taken to the British Museum, the wrist has the form attributed to that 
species, and in the other, that attributed to S. phalangium. Both of these 
individuals were added to that collection. The Sten. Egyptius, Edw., it 
need hardly be remarked, is quite different from those under considera- 
tion ; it is alluded to in consequence of being the only other species of 
the genus. 
The questions occur : — is the S. tenuirostris a deep-water, a local, or a 
geographical variety? The following remarks, though all that can be 
given, have not any very definite bearing on these points. Leach men- 
tions it as a very common inhabitant of all the deep water off the coast 
of South Devon. Couch in his Cornish Fauna, part 1, p. 64, states that 
it is “ common at the depth of from 2 to 20 fathoms.” M. Edwards says 
of S. longirostris, Fabr. (sp.), which he makes synonymous with <S. 
tenuirostris, Leach, — but Mr. Bell thinks that they may be distinct, — that 
it inhabits the Manche and the Mediterranean. 
S. phalangium is noted by Leach as “ very common in the mouths of 
rivers and in estuaries.” Couch has never met with it on the coast of 
Cornwall. M. Edwards notes it as very common on the coasts of the 
Manche and the Ocean. 
Oct. 10 tli, 1851. — Stenorhynchus phalangium. — I found one cast ashore 
to-day on the beach North of Newcastle. 
Genus ACH^EUS. 
A. Cranchii, Leach. 
In the collection of Crustacea formed by Mr. J. V. Thompson, and now- 
in the possession of the Boyal Dublin Society, is a native specimen of 
this crab, which, we may presume, was obtained on the southern coast.. 
Cove, Cork Fauna. 
2 B 
