TRANSACTIONS OF SECTION D. 603 
is longer than the second and bears three well-developed seta, while in B, brevi- 
cornis the terminal joint is much reduced and bears three very slender short sete. 
Gaetanus Holtit.—This species has the upright cepbalic spine of Gaetanus miles 
and the short antennie and three-jointed exopodite of the first foot of G. armiger, 
and thus forms a link between the two sections of the genus. It differs from all 
previously described species in having a spine on the outer edge of the first joint 
of the exopodite of first foot. Length, 5°] mm. 
Gaetanus minor.—This, the smallest member of the genus, has the short an- 
tenn and forward-directed spine of G. armiger. It is alone in having a one- 
jointed endopodite to its second foot. Length, 2°4 mm, 
Scolecithrix emarginata.—This is a large species with a very short abdomen. 
The last thoracic segment is emarginate. The fifth feet somewhat resemble those 
of S. cristata. First antenne slightly longer than the bedy. Length, 43 mm, 
Scolecithrix ovata.— This species is allied to 8. dentata, but differs from it in 
the form of the fifth foot, which consists of a broad oval lamellar joint arising 
from a small basal. It bears a short backward directed spine on its inner margin, 
and a more distal very short spine also on the inner margin. Length, 2°3 mm. 
Scolecithriv echinata.—This species is closely allied to S. brevicornis, but 
differs in the proportional length of the abdomen, which is contained four times in 
the cephalothorax instead of 2} times asin that species The fifth feet also differ 
in the proportional length of their spines. Length, 1°92 mm. 
Xanthocalanus Greenii ? —This is a very large, robust species, with short ab- 
domen ; the fifth thoracic segments are slightly produced externally, but are not 
acute; fifth feet very small, three-jointed, the last joint with three spines, one 
terminal and two lateral. The amima! measures6 mm. in length, and is in conse- 
quence the largest of the genus. 
Xanthocalanus pinguis 9.—This species is moderately robust, with fifth 
thoracic segments produced and swollen, but ending bluntly. The first antennz do 
not reach beyond the fourth thoracic segment. The fifth feet are three-jointed, 
the last joint with four spines, two terminal and two lateral. Length, 4.5 mm. 
Xanthocalanus obtusus 9, .—This species is short androbust. The fifth thoracic 
segments are not produced, and end in a very obtuse angle on either side. The 
fifth feet. are three-jointed, the second joint being the largest; the terminal joint 
has two lateral and two terminal spines. Length, 2-4 mm. 
Osthrix bidentatus.—I have thought it necessary to create a new genus for this 
species, It is very closely allied to the genus Xanthocalanus, and differs mainly in 
the form of the rostrum, which is broad and truncate, and in the terminal 
sensory filaments of the first maxillipede, which are short and swollen instead of 
long and vermicular. 
In the species, and possibly in the genus, the fifth thoracic segment is produced 
on each side into a pair of sharp points. The fifth feet are as in Xanthocalanus. 
Length, 3 mm. 
Lucicutia curta,—This species seems intermediate between L. plancornis and 
L. longicornis. The first to fourth feet have three-jointed exopods and endopods. 
Terminal spine of exopod of fifth foot is contained 13rd times in the length of the 
third joint. First antenne slightly longer than the body. Length, 2.4 mm. 
Aegisthus spinulosus.—This species approaches A. aculeatus in general form, but 
the segmentation between the first and second abdominal segments is complete, 
and the cbitinous reticulations on the cephalon are absent. There is a small two- 
jointed exopod present on the mandible. 
11. On a New Species of Dolichoglossus.' By W. M. Tarrersatt, B.Sc. 
The little Enteropneust described below is the first member of the group 
recorded for British waters. It is true that a species of Balanoglossus occurs in 
the Channel Islands, but that zoologically is in France. 
1 ¥ull descriptions and figures will appear in the Reports of the Department of 
Agriculture for Ireland. 
