MOLGULA SIMPLEX. 58 



loop of the intestine reaches to the dorsal margin ; but 

 the upper loop is comparatively short and extends 

 only about half way across the body. The liver is 

 distinctly lobed and laminated ; and the anal orifice is 

 margined by a rim of nine or ten reflected processes. 



The reproductive organs are considerably elongated 

 and pretty-regularly elliptical, and the margins, when 

 seen from the exterior, present a double series of 

 ovarian lobules ; the oviducts are short, constricted, 

 and directed towards the atrium. The male cseca, 

 which are extremely minute, form on the opposite or 

 inner side of the masses two or three large irregularly- 

 rounded nodules. 



Molgida simplex has much the external appearance 

 of Eugyra arenosa, agreeing with it in size and form, 

 but differing in the absence of the sandy covering. 



t/ O 



An examination of the branchia, however, will at once 

 show the distinctness of the two species. If. simplex 

 has also considerable resemblance to the As<-iiUn inpul- 

 loidesof Van Beneden, which is undoubtedly &Mol<jnla. 

 That species appears to be larger than ours and to 

 have more extended tubes ; the test, too, is described 

 as being solid and thick, which is not the case here. 



6. Molgula siphonata Alder. 



(PL XXV, figs. 4-6; PL XXVI, figs. 1-4; PL XL, 

 figs. 1 and 2 ; and figs. 42 and 43 in text.) 



Molgula siphonata ALDER in Trans. Tyiieside Nat. Field 



Club, I (1850), p. 362. 

 Molgula siphonalis SAKS in Forh. Vid.-Selsk. Christ. 1858 



(1859), p. 65. 



Bod ij roundish or oval, inflated, closely covered with 

 a coating of fine sand; attached by a small base. 

 Apertures long, non-retractile tubes, nearly terminal, 

 a short distance apart, covered with sand like the 

 body ; branchial tube about a quarter of an inch long 

 and as wide; atrial longer and narrower. Test soft, 



