Miscellaneous. 457 
with half the cycle of existence of each of them ; the other is still to 
be discovered. 
I have given to the new insect the name of Ritsemia, in honour 
of M. C. Ritsema, the curator of the Museum at Leyden, who is 
well known in the entomological world. I have added the specific 
name pupifera, to recall to mind the mode of reproduction (antho- 
genesis), in which there intervenes a form furnishing male and 
female pupae, from which the sexual individuals issue and copulate 
immediately. It is this form that I have called “ Pseudogyne pupi- 
fere.” This form exists among the Phylloxera and all the Pem- 
phigians. I find it here among the Coccidae.— Comptes Rendus, 
April 28, 1879, p. 870. 
On Gordius, and on some Parasites of the Rat. 
Prof. Leidy exhibited a curious knotted mass of living hairworms 
(Gordius robustus ?) which had been sent to him by Dr. S. T. Roman, 
of Conowingo, Cecil Co., Md. The mass had been picked up in a 
gutter at the edge of a forest near Conowingo, on the rainy morning 
of Dec. 15,1878. It contained fifty-two male individuals, and seven 
females. The former ranged from 8 to 25 centims. in length, by 
| to of a millim. in thickness; the latter range from 14 to 19§ 
centims. in length, by 1 millim. in thickness. Tho females are 
generally of much lighter colour and more robust character than 
the males. In both sexes the body is most attenuated anteriorly ; 
but in the female tho body is nearly as thick at the posterior ex¬ 
tremity as it is at the middle. Some of tho smaller males are pale 
brownish white ; but most of them, from the smallest to the largest, 
are of various shades of brown to chocolate-brown. The females 
are palo brownish to darker brownish. In both sexes the head 
forms a convex whitish eminence, encircled by a narrow black ring, 
from which a band of brown extends dorsally and ventrally along 
the body. The posterior end of tho body is likewise of darker colour 
than tho part just in advance. 
The tail of tho male makes a spiral turn inwardly and is furcate. 
The forks are short, curved, slightly divergent, blunt conical pro¬ 
cesses. Just in advance of their conjunction internally there exists 
an inverted crescentic fold of browner colour than the contiguous 
parts ; and immediately in advance is the genital pore. The interval 
of the caudal forks is smooth, or free from papilla}. 
The tail of the female appears truncated, is bluntly rounded, 
feebly clavate, or slightly thicker than just in advance, and nearly 
as thick as the middle of the body. It presents a terminal pore, 
marked by a brown spot and encircled with a brown ring. 
Under a moderate magnifying-power, the brown integument is 
minutely mottled with whitish spots, and it exhibits fine longitu¬ 
dinal and diagonal striation. In sunlight it is beautifully irides¬ 
cent as in the earthworm. 
The worms are still quite lively. When disentangled and left 
Ann. & Mag. N. Hist. Ser. 5. Vol. iii. 32 
