18 Dr. J. Anderson on a new Species of Saceulina. 
this parasite appears to be of frequent oceurrence on the Irish 
coast. Some years ago, I found this species for the first time in 
the Firth of Forth, but not nearly in such numbers as the fol- 
lowing one. 
Sacculina triangularis, n. sp., figs. 4, 11, 14. 
Diagnosis.—Triangularis est, gregaria, raro sola; maxima diametro 
ab pedunculo ad pasterine foramen pertinente: parasitus Canert 
paguri. : 
This species is usually gregarious ; sometimes as many as five 
individuals may be found huddled together and struggling for 
existence. I have never found it on any other crab than Cancer 
payurus. Of the two species of these parasites found in the 
Firth of Forth, this is by far the most common: in some locali- 
ties, along the coast, to find a crab free from it is the excep- 
tion. 
The form of the animal is triangular. The greatest diameter 
is in the longitudinal direction, z.¢. from its attachment to the 
posterior orifice. Besides differing in its external characters 
from Sacculina carcini, it also differs from it, as already noticed, 
in the form and position of the vesicles. 
I am indebted to Prof. Goodsir for a specimen of this parasite 
found in the collection of his lamented brother, the late H. D.S8. 
Goodsir. It is a large specimen, apparently distended with ova, 
and adhering to the purse of a Cancer pagurus. 
Sacculina inflata, Leuckart, fig. 15 (Wiegmann’s Archiv, 1859, 
p. 282.) ; 
Diagnosis.—Dorsi et ventris superficies multum arcuata est; pos- 
teriore foramine a corporis margine aliquantum remoto : parasitica 
in Hyade araneo. 
I only know of this species through the description given of 
it by its discoverer. 
BIBLIOGRAPHY. 
Cavournt. Sulla Generazione dei Pesci e deiGranchi. 4to, Naples, 
1787. 
Tuompson, W. Entomol. Magaz. vol. iii. 1836, pp. 452-456. 
Ratuke. Beitr. zur Fauna Norwegens, 1842, pp. 244-247, tab. 12. 
figs. 18, 19. Neueste Schriften der Nat. Ges. in Danz. 
Bett, Tuos. A History of the British Stalk-eyed Crustacea, p. 108. 
Scumipt, O. Das Weltall, No. 3, 1854. 
Sreenstrup. Oversigt k. Danske Selsk. Forhandlgr. 1854, ake 
pp. 145-158. Archiv f. Naturg. 21. Jahr. 1855, Bd. 
pp. 15-19. Ann. of Nat. Hist. 2 ser. vol. xvi. 1855, pp. 155- 
162. 
DresinaG. Systema Helm. vol. i. pp. 434, 435. 
