Subjnniilies, Genera, and Subgenera — Recent and Fossil 91 



ber, Inwc three iiiaiii l)ranches from a single stem, each branch again 

 dividing two or three times, the secondary diverticula being of unequal 

 length. All diverticula arise from the sperm duct in a single series, not in 

 nudtiple series, as in Helisoma. A single branched diverticulum is shown in 

 fig. 6. The diverticulum enters the sperm duct directly and is not placed 

 on a separate duct as in Tropicorbis. The vas deferens (VD) is a narrow 

 tube about 10 mm. long, of less diameter than the sperm duct. 



The i)enial comj^jlcx (fig. 10) consists of an elongated, cylindrical, sac- 

 like preputium (PR) , about 4 mm. long and 0.7 mm. wide and of about the 

 same diameter throughout its length. The very narrow vergic sac (VS) is 

 3 mm. long or slightly shorter than the preputium. It is not much greater 

 in diameter than the vas deferens. There is a rounded enlargement of the 

 vergic sac at the end receiving the vas deferens. There are several sets of 

 muscles. A wide retractor muscle (RM) comi^osed of several smaller 

 branches, is attached to the ui:)per part of the preputium and to the colu- 

 mellar nmscle. On the same side of the preputium there is a wide muscle 

 about midway of its length and two smaller muscles near the male open- 

 ing which appear to be supporting muscles since they are attached to the 

 mantle above the penial complex. On the opposite side of the preputium 

 there is a narrow muscle attached to the upper part near the insertion of 

 the vergic sac, and a very wide muscle or set of small muscles which are 

 attached to the roof of the mantle cavity and are presumed to be support- 

 ing muscles (SM). Some of these may aid in retracting the I'jcnial complex 

 after coitus. 



Internally (fig. 9) there are two wide, heavy pilasters in the preputium 

 tapering to a point at the upper part of the preputial space. The space 

 between the pilasters is marked by many cross muscles forming a reticu- 

 lated pattern (PL). There is a flattened muscular ring or diaphragm (D). 

 The verge (V) is long and very narrow. It tapers to a point and the sperm 

 canal is placed at the center (fig. 5). There is no penial papilla. 



Female Organs. The spermatheca is pear-shaped (S) and the duct 

 (SD) is narrow and as long as the spermatheca. Both gland and duct 

 measure a trifle more than 3 mm. in length. The vagina (VG) is very short 

 and wide. The uterus is the same width as the vagina and gradually en- 

 larges in diameter to meet the nidamental gland (NG) which is very long 

 and wide (about 8 mm. long, 1.5 mm. wide). A part of the uterus projects 

 behind the nidamental gland for several millimeters. The oviduct (OD) 

 is a narrow tube extending from the ovisperm duct backward. It is about 

 twice the diameter of the sperm duct and is about 18 mm. in length. There 

 is a rounded carrefour (OF) extending from the oviduct to which the duct 

 of the albumen gland is attached. The albumen gland (fig. 8) is rectangular 

 in form and is composed of large follicles. The space for the passage of the 

 intestine (IX) is quite conspicuous. 



Hermaphrodite Organs. The ovisperm duct (SO) is very long (17 

 mm.) and is a simple tube except for the portion occupied by the seminal 

 vesicle. The ovotestis is composed of multiple diverticula as seen in situ 

 (fig. 10, OT). In cross section (fig. 4) the ovotestis appears to consist of a 

 main diverticulum (fig. 1) upon which a number of short divertictila are 

 attached (2). The organ is not multiple in the same sense that Helisoma 

 is, which is observed to be fan-shaped in section. Several of the diverticula 

 contained one large ovum ready for exi)ulsi()n. 



