142 Macuray Memortat VoLumeE. 
CRrASPEDELLA Spencert. Plate xu. fig. 21, and Plate xv. fig. 3. 
The general shape of the animal, which is very small, averaging less than 2mm. 
in length, is similar to that of Zemnocephala minor. In front there are five subequal 
tapering tentacles; these are covered with rows (two lateral, two dorsal) of conical 
papille ‘01mm. in length, about twelve in each row. Along the lateral and posterior 
borders are similar, but smaller, papille, arranged at pretty wide intervals. In 
the posterior half of the body, on the dorsal surface, are three thin transverse 
lamelle, ‘05mm. in breadth, divided into about 15-20 rounded lobes, each tipped 
with a few papille similar to those on the lateral borders. Behind the last lamella 
are four conical processes projecting backwards and outwards, each with several minor 
elevations, all of these being tipped with a number of papille. The eyes are situated 
close together some distance behind the bases of the tentacles; the pigment of 
the eyes is in comparatively large rounded granules. There is no other pigment 
in the body. 
The integument is similar to that of Temmnocephala. it is devoid of vibratile cilia. 
The mouth is in the usual position, and leads into a very small chamber representing 
mouth-cavity and pharynx. The intestine appears squarish in outline when 
viewed from above or below, and somewhat unsymmetrical behind, owing to the 
position of the reproductive apparatus. It exhibits no trace of subdivision by 
means of septa. 
The excretory system corresponds closely with that of Temmnocephala. The 
same holds good of the integumentary glands and of the nervous system. 
The anterior testis is oval, smaller than the posterior, situated at the side of the 
posterior part of the intestine. The posterior, irregularly triangular in outline, is 
situated altogether behind the intestine ; the bulb of the cirrus lies between the two. 
The spermatozoa are similar to those of Temnocephala. 
The cirrus (Pl. xt. fig. 21) is strongly curved, with a comparatively long and 
narrow introvert provided with numerous short spines. 
This species, the only member of the genus as yet discovered, lives in the 
branchial chambers of As¢acopsis bicarinatus, climbing about actively among the 
gill-filaments. One specimen, however, was found outside the branchial cavities on 
the surface of the crayfish. 
