167 



33. Sphaeronella affinis n. sp. 



(Pl.X, fig.3a-3d.) 



FEMALE. The only specimen in hand is '87 mm. long, -90 mm. broad, and its 

 thickness is about 8 A of its breadth ; seen from below (fig. 3 a), it is posteriorly broad and 

 flatly rounded, anteriorly somewhat produced, and its lateral outline a little concave at some 

 distance from the head. The head is small, well defined, somewhat broader than long (fig. 3 c) 

 and thus considerably narrower than in S. curtipes. The frontal margin curves strongly 

 forward and is naked. Antennulse, maxillulse and maxillipeds exactly like those of the pre- 

 ceding species, whereas the mouth-border is a little narrower. Basal joint of the maxillae a 

 little less clumsy, with two tolerably small processes situated at some distance from each 

 other where the inner and lower sides meet. The sub-median skeleton has a narrow list 

 inside the maxilhe, and behind their base a transverse stripe of long hairs (drawn only on 

 one side in the figure). The lateral margin of the head has a rather narrow stripe of 

 tolerably short hairs, and this covering does not continue upward on the lateral surface of 

 the head. Somewhat more than the anterior half of the trunk is furnished with short hairs; 

 trunk-legs are wanting. Genital area much larger than the head (fig. 3 a), consisting of a 

 fairly solid, yellowish, centrally somewhat thinner and lighter plate (fig. 3d), which is con- 

 siderably broader than long, rounded; its anterior margin is almost straight, its posterior 

 margin convex; a little behind the middle the proportionally very small genital apertures 

 are situated close together, their muscles turning outward and a little forward and reaching 

 beyond half the distance towards the margin of the plate. The area is naked, except the 

 part between the genital apertures, which is provided with a number of short hairs; caudal 

 stylets I have not been able to find. (Pig. 3d. shows a fragment of the stalk of a sperma- 

 tophore and the outlines of both receptacula seminis.) 



MALE. Unknown. 



OVISACS. With a female occurred six ovisacs mutually glued together, all of 

 them short and broad, somewhat angular, the largest a little flattened; none of them con- 

 tained advanced larvae. They differed very much in size, the largest being - 77 mm. in length, 

 the specimen drawn (fig. 3b) -63 mm. long and broad, the smallest -47 mm. long. The eggs 

 numerous and tolerably small. 



LARVA and POST-LARVAL DEVELOPMENT. Unknown. 



HABITAT. The marsupium of Janira maculosa Leach from Hero, Norway. Prof. 

 G. 0. Sars discovered a single infested specimen and lent it me ; I found one female, the 

 posterior half of which was surrounded by six ovisacs mutually glued together. The parasite 

 was lying with its head turned obliquely forward and somewhat sideways. — An examination 

 of our pretty considerable material of this Isopod from Greenland and Denmark gave a 

 negative result. 



