and on Six New Species of Crustacete, ^c. Id7 



the Geometer moths, as mentioned by Montague. They 

 sometimes walk in this way for a considerable time, and then 

 suddenly stop, remaining perfectly motionless, not even mov- 

 ing their antennae. I have never seen them swim, and even 

 when pushed off their resting-place, they fall listlessly to the 

 bottom of the vessel in which they are confined. 



Caprellu. Lamarck. 



(jiettQfric cAarac^er*.— Branchial lamellee, two pairs attached td the S6C6ind 

 and third segments, which are apodal.* 



Body armed with Spines. 

 Plate III. Fiff. 1. 



Caprella spinosa. — One spine arises from the dorsum of the headj another 

 from the posterior extremity of the post-occipital segment, other two 

 arise in the same transverse line on the dorsum of the swellings of the 

 first thoracic segment, and a fifth from the posterior extremity of this 

 segment. Superior antennce as long, or almost as long, as the body, 

 last joint multiarticulate. Swelling on the first thoracic segment near 

 the anterior extremity. Two spines on the lower edge of the last joint 

 of the second pair of feet. Long, 1 inch ; hab., Frith of Forth. 



Description. — The whole body of a pale white colour, with the exception 

 of the eyes, which are black. The dorsal surfaces of the two first seg- 

 ments of the body are armed with long sharp curved spines, which 

 point forwards ; one arises from the vertex of the head, another from 

 the posterior^ extremity of the post-occipital segment, other two arise 

 in the same transverse line from the swelling on the first thoracic seg- 

 ment, and a fifth from the distal extremity of the same segment. Su- 

 perior antennse as long as the body ; first joint obsolete ; second and 

 fourth as long as the head and post-occipital segment conjoined ; third 

 almost twice as long ; fifth multiarticulate, and as long as all the others 

 conjoined ; it is composed of about 26 articulations ; fourth articulation 

 slightly clavate. Inferior antennee a little longer than the three first 

 joints of the superior antennse ; the two first joints equal in length to 

 the palpi, the third reaching a little beyond the second joint of the 

 superior pair, fourth and fifth reaching beyond the third, fifth triarticu- 

 late. 



Head rounded considerably, produced inferiorly, eyes circular, blacks 

 and reticulated ; post-occipital segment twice as long as the head; firs^ 

 thoracic segment with tlie swelling before the middle, and a spine point- 

 ing forwards immediately above the origin of the second pair of legs ; 

 femoral joint davate, twice the length of the first thoracic segment ; last 



• Dt Johnston, 8tb vol. of Mag. Nat. Hist. p. 669. 



