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HABITAT. The marsupium of Ampelisca macrocephala Lilljeborg from Denmark. 
Only a single infested specimen has been found, and in the anterior part of its marsupium 
occurred: a deformed female, which had probably finished laying eggs, one male and seven 
mutually adhering ovisacs, one of which contained full-grown larvee; in the hindmost part 
appeared the large female represented, one male and six mutually adhering ovisacs; one 
ovisac had fallen out before its place was ascertained. 
REMARKS. The name of the species points to the remarkable cup on the frontal 
margin of the female. The male deviates much from all other hitherto known forms. 
26. Sphzronella microcephala Giard and Bonnier. 
(Pl. VII, fig. 2a—2k). 
Spheronella microcephala Giard and Bonnier, Compt.-rend. de !’Acad. des Sc., 25 sept. 1893. 
— — _— Bull. scientifique de la France et de la Belgique, T. XXV, 
fase. 2, 1895, p. 464, pl. XII, fig. 40—47. 
FEMALE. The largest specimen, which had only just begun laying eggs, was 
144mm. in length and of the same breadth and thickness (fig. 2a), sub-globular, yet a little 
produced and almost pointed towards the front, which is due to the fact that the trunk 
merges evenly into the head without any separation. The frontal border is present as a 
small crescent-shaped transverse plate (fig.2e), which is scarcely double the length of the 
diameter of the mouth; lateral borders are wanting (fig. 2d); so we only find the various 
appendages and a tolerably developed sub-median skeleton, but, as the lateral parts of the 
skeleton, viz. the lateral borders, are wanting, this parasite differs from all the preceding, 
but agrees with several of the following species of this genus, im having no lateral limitation 
to the surroundings of the mouth-limbs. Antennulz very short, without distinct vestiges of 
articulation, with a seta on the anterior margin at a short distance from the base (no doubt 
corresponding to the usual pretty long seta at the anterior angle of the first joint), and 
four terminal sete of unequal length, the longest of which are a little longer than the 
antennula. Antenne seem to be altogether wanting. The mouth of medium size, with a 
rather narrow mouth-border. Maxillule well developed, with good-sized additional branch. 
Maxille far removed from the rostrum and much closer together than in any other species 
of the genus; the basal joint large and smooth. Maxillipeds small and feeble; their basal 
joint pretty short, very slender and naked, the second and third joints fused into a very 
short and slender joint; the last joint scarcely half the length of the preceding, rounded at 
the end; the reduced state of the two (or three) last joints, in particular, proves this pair 
of appendages to be almost valueless as prehensile organs. The sub-median skeleton is 
provided with a somewhat prominent list on each side of and at a short distance from the 
19 
